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Karina Jimenez

The Prospect of Pharmacogenetics in Pediatrics

By | Opioids, Other, Pharmacogenetic Testing, Provider | No Comments

Pharmacogenetics of Opioids as a Potential Alternative in Pediatric Pain Management

Opioid and codeine treatment in pain management for children has been a primary concern in clinical settings, specifically for surgical pain management. The concerns are the adverse reactions caused by the opioids, such as respiratory depression. Current Opinion in Anesthesiology, “Codeine and Opioid Metabolism: Implications and Alternatives for Pediatric Pain Management” (2017), reviews how important clinical factors and genetic polymorphisms affect the metabolism of opioids after surgical operations.


Adverse Side Effects of Codeine

Codeine’s efficacy has been questioned in the pain management of children. Current Opinion in Anesthesiology identifies the adverse reactions of it. The prominent ones are respiratory depression, anoxic brain injuries, and even death occurring in children. With reported doses of codeine, significant respiratory depression was found in newborns in a report by Canadian Pharmacists Journal “Pain Management in Children: A Transition from Codeine to Morphine for Moderate to Severe Pain in Children” (2012).

Opioids in Pain Management

Opioids are the cornerstone of pain and chronic pain management. “Successful pain management provides adequate analgesia without excessive adverse reactions affirms Clinical Biochemistry “Pharmacogenetics of Chronic Pain Management” (2014). Drug metabolism and responses are influenced by numerous factors, including pharmacogenetics. Genetic variations contribute to the distinct inter individual responses to pain medications.

Involvement of CYP2D6 in Codeine

Those with two nonfunctional alleles of CYP2D6 are considered poor metabolizers. Extensive metabolizers have one or two effective CYP2D6 alleles and those with duplicated CYP2D6 alleles are ultra rapid metabolizers. Canadian Pharmacists Journal indicates the functions of CYP2D6 are similar in both children and adults.

The review also acknowledges the safety concerns of CYP2D6 ultra rapid metabolizers from several studies. One study demonstrated how a breastfed newborn infant died after his mother consumed Tylenol #3 for postpartum pain. Toxicology testing found the mother had abnormally high concentration levels of morphine in her breast milk. Genotype testing found the mother was an ultra rapid metabolizer of codeine. The study concluded since the mother was an ultra rapid metabolizer, higher than normal morphine levels crossed into the breast milk and resulted in the infant dying from morphine intoxication.

Another study found a two-year-old child who also died of morphine intoxication. The child was prescribed codeine in recommended dosages after having his tonsils removed. Genotype testing revealed the child was an ultra rapid metabolizer of codeine. However, there were also other contributing factors; the child had bronchopneumonia and sleep apnea. The study concluded these factors “may have increased his risk of hypoxemia, leading to alterations in opioid receptors and increased sensitivity to morphine.”

Canadian Pharmacists Journal concludes these studies show ultra rapid metabolizers of codeine are correlated with a higher risk of morphine intoxication among children.


Alternatives to Prevent Adverse Drug Reactions

Canadian Pharmacists Journal argues morphine as a safer alternative compared to codeine. They argue morphine has “demonstrated efficacy and relative safety when used appropriately in pain management in both adults and children.” A study they analyzed found morphine treatment more effective than a placebo for children in postoperative pain.

Current Opinion in Anesthesiology also outlines the possible alternatives to prevent the risks of opioids, such as pharmacogenetics. They indicate personalized opioid therapy for pain management is “distant from reality”, but current CYP2D6 pharmacogenetic research on codeine is hopeful. The review summarizes, “pharmacogenetics has the potential to guide anesthesia providers on perioperative opioid selection and dosing to maximize efficacy and safety.”

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Pharmacogenetics Emerging as a Method to Guide Medication Therapy

By | Gene Panel, Opioids, Other, Pharmacogenetic Testing, Provider | No Comments

According to a recent article published in American Family Physician “Pharmacogenetics: Using Genetic Data to Guide Drug Therapy (2015), pharmacogenetics is being more widely used by family physicians and the number of patients who are interested in acquiring genetic information is growing.


The Components of Pharmacogenetics Testing

Pharmacogenetics involves genetic variations that code for drug metabolizing enzymes. It also involves how a medication breaks down in the body and how the body responds to the medication. The most common forms of genetic variations are single nucleotide polymorphisms.

The differences in single nucleotide polymorphisms or other polymorphisms result in diverse types of genes or alleles, the American Family Physician explains. Individuals inherit these alleles that “govern expression of the gene and the cor¬responding enzyme or protein.” As a result, these genetic differences influence how the drug reacts in the body and how the body metabolizes the drug.


Genetic Variability Can Alter the Effects of Drugs

Studies have demonstrated there is a connection between genetic variations and changes in drug levels and effects.

CYP2D6 and Opioids

The enzyme activity of CYP2D6 is volatile because of single nucleotide polymorphisms and other variations of CYP2D6. American Family Physician indicates codeine metabolism occurs in 90% of patients and results in normal morphine formation. However, 1% to 2% of people are ultra rapid metabolizers of codeine signifying they have an increased risk of morphine toxicity.

American Family Physician analyzed a study involving the death of a breastfed infant and a mother who was an ultra rapid metabolizer of codeine. The study demonstrated the infant died of morphine intoxication. There was opioid toxicity in the breast milk, which passed onto the infant.

They recommend pharmacogenetic testing for patients who are possible poor or ultra rapid metabolizers of opioids.


CYP2C19 and Clopidrogrel

Clopidogrel is primarily metabolized in the enzyme CYP2C19. CYP2C19 is highly polymorphic and 80% of individuals metabolize clopidogrel normally. However, 18% to 45% of people have intermediate enzyme activity and 2% to 15% have poor enzyme activity.

American Family Physician presents meta-analyses of CYP2C19 poor metabolizers. Poor CYP2C19 metabolizers taking clopidogrel treatment and undergoing percutaneous coronary intervention have a higher risk of cardiovascular death, myocardial infraction, stroke, and stent thrombosis.

These results lead to the recommendation that clinicians should consider alternative treatments, such as pharmacogenetic testing of CYP2C19 to guide antiplatelet therapy.


The Benefits of Pharmacogenetics

American Family Physician examined the clinical implications of pharmacogenetic testing and the various resources available and developing to support the usage of pharmacogenetics in clinical settings. They conclude “pharmacogenetic testing can be a practical tool to optimize drug therapy and avoid medication adverse effects.”

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Statin Side Effects: From Muscle Soreness to Rhabdomyolysis

By | Adverse Drug Reactions, Statins | No Comments

Statins are drugs used to lower cholesterol. They are effective agents for treating high cholesterol, enabling your liver to remove cholesterol from your blood, which lowers your total cholesterol. Lowering LDL (low-density lipoprotein, or “bad”) cholesterol results in substantial reductions in cardiac events. Statins also help prevent other cardiovascular diseases, such as chest pain, heart attacks, strokes, and certain blood vessel problems (Pharmacy Times “Statins Provide Heart Benefits Besides Cholesterol Lowering” June 1 2017).


Statins approved for use in the United States include the following agents: atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), pravastatin (Pravachol), rosuvastatin (Crestor), simvastatin (Zocor), and pitavastatin (Livalo).

One of the most common unwanted symptoms from taking statins is muscle pain, muscle soreness, muscle fatigue, and muscle weakness. People who take statins shouldn’t drink large quantities of grapefruit juice, as this is associated with the muscle pain side effects. Statins may affect specific enzymes present in muscle cells that are responsible for muscle growth. The muscle pain is located in skeletal muscle, and the side effects range from slight myalgia to severe rhabdomyolysis.


Rhabdomyolysis: Rapid Breakdown of Skeletal Muscle

Rhabdomyolysis is a serious condition in which the destruction of striated muscle tissue, or skeletal muscle, releases muscle enzymes such as myoglobin and electrolytes from inside the muscle cells. If you have too much myoglobin in your bloodstream it can cause kidney damage. If treated early, rhabdomyolysis may be stopped.   This condition is treated with fluids given in an IV drip. Some people may require dialysis or hemofiltration (therapy filtering bad waste and products from blood) to address the more severe cases.

Early symptoms of rhabdomyolysis may be vague as they are not specific and may mimic other conditions. The symptoms of rhabdomyolysis include:


  • Muscle weakness
  • Fatigue
  • Low urine output
  • Bruising/soreness
  • Dark or tea-colored urine
  • Infrequent urination
  • Fever
  • Malaise (discomfort)
  • Nausea/vomiting
  • Confusion
  • Agitation

Although only a minimal number of people get rhabdomyolysis, many people take these medications and it is important to be aware of the risks.


Importance of Determining Muscle and Kidney Health

There are several tests to check muscle and kidney health. Creatine kinase levels should be tested, as it is an enzyme found in the skeletal muscles, the brain, and the heart. Myoglobin levels in the blood and urine should also be tested, as myoglobin is a protein that is a byproduct of muscle breakdown. Potassium is an important mineral that may leak from injured muscles and should be tested as well. Lastly, creatine in blood and urine should be tested, as creatine is a breakdown product created by muscle that is normally removed from the body by the kidneys.

Rhabdomyolysis can be successfully treated without long-term damage to the kidneys if it is treated early. Fluid recovery is essential and is the first and most important treatment.


Statin Muscle Side Effects and Pharmacogenetics

Although few patients experience muscle pain and the associated serious side effects, it has been suggested that the basis for this reaction is genetic. Once the human genome was sequenced and completed, the field of pharmacogenetics could advance its knowledge base. Pharmacogenetics is an important medical field that studies the genes that are responsible for drug metabolism and related events. Advances in the wider field of pharmacogenomics showed that in a genome wide study, muscle myopathy was associated with single nucleotide polymorphisms (SNPs) in the gene SLCO1B1. Those authors identified common genetic variants in SLCO1B1 that are strongly associated with statin-induced myopathy.


Know Your Risks with the Rxight® Pharmacogenetic Test

Genotyping using the Rxight® pharmacogenetics test from MD Labs may help patients receive the benefits of statin therapy without the muscle-associated side effects. Pharmacogenetics testing with the Rxight® platform from MD Labs is an advanced, state-of-the-art method to test many gene variations in your individual genome that may be responsible for adverse effects with statins and over 200 other drugs on the market. This precision medicine approach to personalized care is now available by prescription.

Ask your physician to prescribe the Rxight® pharmacogenetics test from MD Labs. You and your physician may use these results over the lifetime of your care, as many genes are tested for variations that are responsible for adverse side effects not only in statins, but also in the majority of drugs on the market.

These results inform your physician about what drugs you may safely take, and what drugs are not recommended for you, in addition to giving dosing schedules that might be different from label instructions. Participating in this precision medicine advance may lead to lessened side effects over the course of your lifetime pharmaceutical treatments.



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The Pharmacogenetics of Antiplatelet Agents: Meta-Analyses of Aspirin and Clopidogrel Loss-of-Function Alleles

By | Gene Panel, Other, Pharmacogenetic Testing | No Comments

Antiplatelet agents combined with aspirin have been shown to play a significant role in mitigating the effects of coronary disease, and ample research has found that distinct genetics determine patients’ response to clinically significant antiplatelet agents.


Platelets play a decisive role during the formation of an initial hemostatic plug through their intricate response to injury. When inappropriately activated, platelets contribute to pathological thrombus formation. Arterial thrombus formation can then lead to tissue ischemia causing potentially fatal coronary and cerebrovascular events.


Interindividual Genetic Variation Impacts Aspirin Antiplatelet Efficacy


Aspirin is regarded as “the cornerstone for secondary cardiovascular prevention,” the efficacy of it, which has long been established, as noted in Current Pharmaceutical Design, “Pharmacogenetics of the Antiplatelet Effect of Aspirin” (2012).


The researchers avert that there is considerable interindividual variation in response to aspirin, thus reducing its efficacy in treating heart disease in some patients.


P1A2 and P2Y1 Association with Decreased Aspirin Antiplatelet Efficacy


Specifically, the review conducted by Current Pharmaceutical Design examined polymorphisms of genes that contributed highly to antiplatelet responses. These were P1A2 from glycoprotein GP IIb/IIIa, and the P2Y1 polymorphism from AD receptor (ADP) genes.


P1A2 was characterized as having an association with coronary thrombus formation. One study showed P1A2 allele was related with a shorter baseline bleeding time in comparison to a wild type allele. After measuring bleeding after aspirin ingestion, there was a reduced antiplatelet effect.


Another study supported this finding by discovering an enhanced thrombin formation in P1A2 carriers compared to P1A1/A1 homozygotes before and after aspirin ingestion. The review concluded that P1/A2 polymorphism is a prothrombotic platelet phenotype responding inadequately to aspirin.


Polymorphism P2Y1 was utilized in an arachidonic acid-induced optical platelet aggregometry to assess its antiplatelet effect of aspirin. The results showed that the T allele of the C893T P2Y1 polymorphism was substantially linked with a decreased antiplatelet effect of aspirin.


CYP2C19 Mediates Clopidogrel Non-Response


Evidence for association of CYP2C19 with clopidogrel response was investigated in the Journal of Human Genetics “Pharmacogenomics of Anti-Platelet Therapy: How Much Evidence is Enough for Clinical Implementation?” (June 2013).


The study established CYP2C19 as a genetic factor contributing to the creation of the active metabolite of clopidogrel. A corresponding analysis detailing the associations of CYP2C19 alleles and increasing residual on-treatment platelet reactivity corroborated this finding. The study concluded that patients with even one reduced function of CYP2C19 and taking clopidogrel as treatment for percutaneous coronary intervention may be “associated with increased risk of major adverse cardiovascular events as a consequence of aspirin antiplatelet inefficacy.”


The International Journal of Environmental Research and Public Health “Pharmacokinetic and Pharmacodynamics Responses to Clopidogrel” (February 2017) also reviewed the connection between CYP2C19 and clopidogrel. The review was based on the authors’ argument that genetic polymorphisms impact the absorbtion and metabolism of clopidogrel and that the P2Y12 receptor may interfere with its antiplatelet activity.


In one meta-analysis, it was found there was a critical relation between CYPC219 loss-of-function in diverse patients with frequent cardiovascular events. In another meta-analysis, CYPC219 was identified as having a having a crucial part in reducing the active metabolite of clopidogrel.


CYP3A4/5 Mediates Clopidogrel Non-Response


In addition to analyzing clopidogrel, the review also analyzed CYP3A4/5. The authors found that the CYP3A5*3 allele has an influence on clopidogrel metabolism because of its possible dependence on CYP2C19 and CYP3A4 inhibitors. In the study, the patients with a CYP3A5*3/3 genotype displayed enhanced platelet reactivity compared to those with a CYP3A5*1 allele in CYP2C19 poor metabolizers. An additional study reported CYP3A5*3 on clopidogrel response is prominently in patients with the CYP2C19 loss-of-function.



Benefits of Individualizing Antiplatelet Therapy with Pharmacogenetic Testing


Research has been conclusive in identifying potential antiplatelet pharmacogenetic applications pointing to effective individualized treatments, according to the studies.

The review by the International Journal of Environmental Research and Public Health asserted there is an “inter-individual variability” in clopidogrel’s antiplatelet effects. They concluded inadequate platelet responsiveness to clopidogrel has a role in accumulating the risk of cardiovascular events, and therefore increasing drug dosage or switching to alternative drug medications may be more beneficial for patients.

Similarly, the review published in Current Pharmaceutical Design concludes by recommending utilization of antiplatelet pharmacogenetics in clinical practice. “The promise of pharmacogenetics lies in the prospect of improving treatment efficacy and safety.”




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Overview of Alprazolam (Xanax) Uses and Side Effects

By | Adverse Drug Reactions, Antianxiety Medications, Other | No Comments

Alprazolam, commonly referred to by its brand name Xanax, is the one of the most common benzodiazepine used. Benzodiazepines like alprazolam are anxiolytics (antianxiety drugs) used in the treatment of a number of diseases including panic disorder, generalized anxiety disorder and social anxiety disorders. Occasionally the drug is used for nausea and vomiting symptoms associated with chemotherapy. (PubMed Health “Alprazolam” May 2017).


Alprazolam Mechanism of Action

Alprazolam, like all benzodiazepines, binds nonspecifically to benzodiazepine receptors at the BDZ site. This bind tightens the connection of GABA with the receptor and results in increasing hyperpolarization of neurons. This mechanism is the base for the drug’s antianxiety effects.


Alprazolam Side Effects

Alprazolam has a significant effect on a major neurotransmitter which results into psychiatric and nervous system side effects. According to the FDA label on Xanax, the most common adverse effects include (occur in more than 1% of patients):


  • Irritability
  • Anxiety
  •  Depression
  •  Confusion
  •  Derealization or alteration of perception
  •  Dream abnormalities
  •  Fear
  •  Disinhibition
  •  Drowsiness (77% of patients)
  • Impaired coordination (40% of patients)
  •  Memory impairment
  • Lightheadedness
  • Insomnia
  • Headache
  •  Cognitive disorder
  •  Dysarthria
  •  Ataxia
  •  Balance disorders
  •  Nasal congestion
  •  Hyperventilation
  •  Upper respiratory tract infections
  • Fatigue/tiredness (49%)
  •  Weakness
  •  Edema (swelling)
  •  Decreased libido (14%) and increased libido
  •  Micturition difficulties (inability to urinate etc)
  •  Menstrual disorders (in females)
  •  Sexual dysfunction
  •  Sweating
  •  Rash
  •  Allergies
  •  Tachycardia (increased heart rate)
  •  Chest pain
  •  Palpitations
  •  Hypotension
  •  Increased appetite (33%)/ decreased appetite (28%)
  •  Weight gain (27%)/ loss (23%)

The Xanax label from the FDA reports Alprazolam has rare side effects, which are anger, self-harm and irregular menstruation. These occur in less than 1% of patients

Risk of Suicide

Research has shown that the use of benzodiazepines can influence suicide risk.  A literature review evaluated studies that involved the relationship between benzodiazepines and concluded there was a significant relationship between increased suicide risk and benzodiazepines (The Primary Companion for CNS Disorders “Prescribed Benzodiazepines and Suicide Risk” March 2017). The results were consistent in different populations and methods used.  The review also found that possible suicidal warnings may include “increases in impulsivity or aggression, rebound or withdrawal symptoms, and toxicity in overdose.”

Alprazolam and Pharmacogenetic Testing

Some patients do not develop any side effects when taking Alprazolam and some do.  This interpatient variability may be due to differences in patients’ genetics. Polymorphisms in the genes that code for enzymes and receptors that interact with Alprazolam have been shown to account for a significant proportion of this inter patient variability.

Alprazolam is metabolized by the cytochrome P450 superfamily of enzymes, namely isoenzymes CYP3A4 and CYP2C9. Polymorphisms in these enzymes have been shown to alter the blood plasma concentrations of the drugs they metabolize. Alleles may alter the probability of individual developing side effects when taking Alprazolam.


Understand Your Genetic Risks for Side Effects with the Rxight Test

Identifying these polymorphisms can aid in clinical decision-making. Knowing a patient has a given polymorphism can result in a clinician altering the starting dose of a medication like Alprazolam, potentially reducing their probability of developing side effects.

MD Labs provides a genetic testing service, Rxight®.  Accurate, reliable, and easy to understand, Rxight® sequences 18 genes to establish how a patient is likely to respond to hundreds of clinically relevant medications (including Alprazolam).

As a key component of precision medicine, Rxight® allows your healthcare provider and pharmacist to see if Alprazolam is right for you and create the best possible treatment for you.  With a simple cheek swab done at your pharmacy, Rxight® will provide you with a DNA Blueprint that minimizes drug’s side effects and proper course for present and future treatments.

Contact us for more information about how Rxight® can benefit you through phone at 1-(888) 888-1932 or email at support@Rxight.com.

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The Possible Connection Between Antianxiety Drug Lorazepam (Ativan) Use and Suicide

By | Adverse Drug Reactions, Antianxiety Medications | No Comments

Lorezapam, also known as the brand name Ativan, is a common antianxiety drug prescribed by psychiatrists. According to Pharmacy Times, it is the 48th most used drug in the United States (Pharmacy Times “Top 200 drugs of 2012,” July 2013). It has received attention in the media recently for its possible implication in the suicide of American rock/grunge musician Chris Cornell (CNN “Chris Cornell Used Prescription Before Death, Toxicology Report Says,” June 2017).

Ativan is a benzodiazepine, which are CNS (central nervous system) depressants that aid in slowing and calming down the central nervous system and thus reducing anxiety. (PubMed Health “Lorazepam” May 2017).

Ativan is also commonly used for insomnia and alcohol withdrawal. In addition, Ativan is used to treat continuous seizures, agitation, irritability, mania, and schizophrenia, and used as medication before anesthesia. (Stanford Medicine “Lorazepam,” 2017).

Ativan is only intended for short-term use. According to Stanford Medicine, if misused, it can cause serious side effects such as acidosis (excess amount of acid in the body), drug dependence, and unusual and dangerous behavior. Moreover Ativan, like other benzodiazepines, is highly addictive causing physical and psychological dependence.


How Ativan is Associated with Suicidal Behaviors

Medical experts report that benzodiazepine could cause anterograde amnesia. Those with anterograde amnesia can exhibit dangerous behaviors, such as intoxicated driving, committing crimes, and attempting suicide. (PubMed “Anterograde Amnesia Linked to Benzodiazepines” October 1992).

A toxicology report recently released showed that seven drugs, including a significant dose of Ativan, were found in Cornell’s system. However, the medical examiner said drugs did not contribute to Cornell’s death, but that instead Cornell committed suicide. (CNN “Chris Cornell Used Prescription Before Death, Toxicology Report Says,” June 2017).

According to experts, long-term use of Ativan can cause depression and negative mood in those with a history of depression and suicidal ideation. However, they advised that if someone was to die of an Ativan overdose or blackout, underlying mental health issues could have also played a role. (American Addiction Centers “The Dangers of Long-Term Use of Ativan” 2017).


Research Confirms Benzodiazepines Use Connected with Self-Harm

Research has shown an association between self- harm and suicide and benzodiazepine usage (The British Journal of General Practice “Self-harm and Suicide Associated with Benzodiaepine Usage” May 2007).

The case report found that a patient self-inflicted stab wounds twice in a month after his benzodiazepine dosage was changed. The researchers also examined another study that showed a significant correlation between benzodiazepine and suicide in the elderly. The report concludes that although these effects are rare, prescribers should be aware of how a strong dependence on benzodiazepine is developed quickly.


Know Your Risks with the Rxight® Genetic Test

If you are taking or plan to take Ativan (lorazepam) and are concerned about side effects such as these, consider the Rxight® genetic test to analyze your genetic risks. Rxight® is a pharmacogenetic program made just for you. Your doctor and pharmacist work together to create an accurate, reliable, and easy to understand treatment plan to minimize harmful drug effects and get you on the right medications.

Contact us for more information about how Rxight® can benefit you through phone at 1-(888) 888-1932 or email at support@Rxight.com.

Antipsychotic Medications in Schizophrenia

By | Antipsychotics, Pharmacogenetic Testing, Pharmacogenomics, Precision Medicine, Psychiatric Medications | No Comments

Medications are central to the treatment of schizophrenia and a number of drugs are used to treat this serious mental condition. Schizophrenia is a long-term mental disorder marked by psychosis- a breakdown in the relation between thought, emotion, and behavior, leading to errors in perception, inappropriate actions and feelings, withdrawal from reality, and a sense of mental fragmentation.


Most patients are now treated with antipsychotics that are thought to control symptoms through the brain chemical, dopamine. There are two types of antipsychotics used: first generation and second generation.


First Generation Antipsychotics

The first generation antipsychotics have more serious side effects and are used only when necessary. They include haloperidol (Haldol), chlorpromazine (Thorazine), and Fluphenazine (Prolixin). Side effects of first-generation antipsychotics include extrapyramidal side effects which is marked by rigidity, bradykinesia, dystonias, tremor, and akathisia. Tardive dyskinesia (TD)— a disorder marked by permanent involuntary movements in the limbs and face such as grimacing and lip-smacking – is another adverse effect that can occur with first-generation antipsychotics. Additionally. first-generation antipsychotics are known to cause cardiac rhythm abnormalities.


Second Generation Antipsychotics and Side Effects

The newer second generation antipsychotics have less side effects than the older drugs, and are preferred for treatment of schizophrenia. They include: aripiprazole (Abilify), asenapine (Saphris), brexipiprazole (Rexulti), clozapine (Clozaril), Iloperidone (Fanapt), Lurasidone (Latuda), Olanzapine (Zyprexa), Paliperidone (Invega), quetiapine (Seroquel), risperidone (Risperdal), and ziprasidone (Geodon).

Abilify side effects include akathisia (agitation), restlessness, insomnia, constipation, fatigue and blurred vision. Most of the second-generation antipsychotics have similar side effects, as they are similar chemically. Geodon is one of the newer antipsychotics with extra-pyramidal side effects reported (drug induced movement disorders).

During initial phases of treatment with the second generation antipsychotics patients may experience side effects such as dry mouth, drowsiness, restlessness, muscle spasms, tremor or blurring of vision. The second generation antipsychotics have a much lower risk of tardive dyskinesia, a serious side effect of the older antipsychotics. It is possible to lessen side effects by either lowering the dose or by changing medications.


Antipsychotic Pharmacogenetics

Patients and physicians often work together to find a dose that results in the fewest side effects. Patients will often change medications if the side effects are severe and side effects lessen over time. One way to potentially avoid side effects for new medications and for newly prescribed schizophrenia medications is to have your drug metabolism genes tested. After the human genome was sequenced back in 2003, genome wide association studies showed that there is variation among the population in the genes that process medications. As a result, if there’s a drug-processing gene with variation, it may have trouble processing medications that are metabolized by that gene product.


Know Your Risks with the Rxight® DNA Test

The most state-of-the-art way to determine genetic variations is with the Rxight® pharmacogenetics test from MD Labs. This advance in pharmacogenetics means that a physician can determine beforehand what drugs may be safe to take and what drugs to avoid or require different doses than recommended. All that is required is a prescription from a physician and a cheek swab at a participating pharmacy.

You could benefit from this advance in precision medicine with the knowledge of your gene variations with your physician or other healthcare services. The Rxight® pharmacogenetics test determines your genetic susceptibilities for over 200 drugs on the market. You could also benefit from knowing how you might respond to drugs you may have to take in the future. Most importantly, you could get information that may change your current dosing and medication for fewer harmful side effects from your antipsychotic medication.

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Uses, Side Effects and Pharmacogenetics of Antihypertensive Drugs

By | Adverse Drug Reactions, Antihypertensives | No Comments

An antihypertensive drug is any agent that reduces blood pressure. There are many different classes and are used in certain situations. They are prescribed for hypertension and help prevent events like transient ischemic attacks (TIAs), strokes, and myocardial infarction.
Classes of antihypertensive drugs include:

  • Diuretics
  • Calcium channel blockers
  • ACE inhibitors – used to treat hypertension but act by inhibiting angiotensin converting enzyme. This reduces activity of the renin angiotensin aldosterone system and reduces blood pressure. One example is ramipril.
  • Angiotensin II receptor antagonists
  • Adrenergic antagonists
  • Benzodiazepines
  • Renin inhibitors
  • Aldosterone receptor antagonists
  • Endothelin receptor blockers
  • Thiazide diuretics – used to treat hypertension and edema. They work by inhibiting the sodium chloride symporter. The increase in fluid loss decreases blood volume and reduced blood pressure. An example is bendroflumethiazide.


Antihypertensive Drugs Side Effects

Thiazide diuretics like bendroflumethiazide cause a number of side effects. These include:

  • Syncope (fainting)
  • Hypotension (low blood pressure)
  • Glaucoma
  • Gastric irritation
  • Nausea/vomiting
  • Diarrhea
  • Constipation
  • Abdominal pain
  • Rash

Calcium Channel Blockers include drugs like isradipine and verapamil. Side effects include:

  • Headache
  • Dizziness
  • Lethargy
  • Hypotension (low blood pressure)
  • Edema (swelling)
  • Pharyngitis (sore throat)
  • Fatigue
  • Malaise
  • Rash
  • Scalp irritation
  • Sleep disturbance
  • Myalgia (muscle pain)
  • Allergic reactions
  • Hypersensitivity
    ACE inhibitors are also associated with a number of side effects. These include:

    • Hypotension
    • Angina pectoris (chest pain)
    • Postural hypotension
    • Nausea/vomiting
    • Diarrhea
    • Abdominal discomfort
    • Dyspepsia
    • Fatigue
    • Asthenia
    • Vertigo
    • Bronchitis
    • Cough
    • Depression
    • Anxiety
    • Nervousness
    • Restlessness
    • Headache
    • Dizziness
    • Syncope (fainting)
    • Muscle spasm
    • Myalgia (muscle pain)

    Angiotensin II receptor antagonists include drugs like losartan (Cozaar). Common side effects include:

    • Nasal congestion
    • Sinusitis
    • Abdominal pain
    • Nausea
    • Diarrhea
    • Dyspepsia (indigestion)
    • Back pain
    • Myalgia (muscle pain)
    • Dizziness
    • Headache
    • Vertigo
    • Chest pain
    • Hyperkalemia (high blood concentration of potassium)
    • Insomnia
    • Anemia

    Adrenergic receptor antagonists are also used as antihypertensives. Common side effects include (these occur in more than 1% of patients):

    • Hypotension (low blood pressure)
    • Raynaud’s syndrome (can result in cold extremities)
    • Fatigue
    • Sleep disturbances
    • Nightmares
    • Sleep disorder
    • Agitation
    • Somnolence (lack of energy)
    • Irritability

    Antianxiety medications such as benzodiazepines can be used to lower blood pressure. Side effects can include:

    • Irritability (33% more)
    • Anxiety
    • Depression
    • Confusion
    • Disinhibition
    • Derealization
    • Dream abnormalities
    • Fear
    • Drowsiness (77%)
    • Impaired coordination
    • Memory impairment
    • Lightheadedness
    • Insomnia
    • Headache
    • Cognitive disorder
    • Dysarthria
    • Abnormal involuntary movement
    • Somnolence
    • Ataxia (loss of control of body)
    • Balance disorder
    • Nervousness
    • Syncope (fainting)
    • Agitation
    • Paresthesia (pins and needles)
    • Tinnitus
    • Hypersomnia
    • Lethargy
    • Fatigue
    • Blurred vision
    • Decreased libido
    • Micturition difficulties (issues urinating)
    • Menstrual disorders
    • Increased libido
    • Decreased salivation
    • Constipation
    • Allergies
    • Tachycardia (increased heart rate)
    • Chest pains
    • Rigidity
    • Tremor
    • Muscular twitching
    • Increased/decreased appetite
    • Weight gain/loss


    Know Your Risks for Side Effects from Anihypertensive Medications with the Rxight® Genetic Test

    Most patients do not suffer adverse reactions when taking antihypertensives. However some patients may suffer from many side effects. This inter patient variability is explained by pharmacogenetics. Polymorphisms (variations) in the enzymes and receptors that interact with antihypertensives can increase the probability of patients developing side effects.
    Most antihypertensives are metabolized by the cytochrome P450 superfamily of enzymes (the specific isoenzymes will vary on class and drug). Polymorphisms in these enzymes have been shown in studies to increase the probability of developing side effects (Clinical Biochemist Reviews, “The Influence of Cytochrome P450 Pharmacogenetics on Disposition of Common Antidepressant and Antipsychotic Medications,” Feb 2006).
    Identifying these alleles can aid clinicians in prescribing antihypertensives and could reduce the risk of developing adverse reactions. MD Labs provides a genetic testing service, Rxight®, which sequences a number of genes to establish how patients are likely to respond to hundreds of medications, including most antihypertensives.

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    side effects of opioids

    Pharmacogenomic Data May Help Guide Opioid Pharmacotherapy in Patients with Cancer-related Pain

    By | Cancer Treatments, Other, Pain Medications, Pharmacogenomics, Provider | No Comments

    Opioids are the most potent analgesics and are used to treat severe pain, specifically pain associated with cancer – a significant factor in reducing quality of life and clinical outcomes in such patients as detailed in Cancer Control “Clinical Implications of Opioid Pharmacogenomics in Patients with Cancer” (October 2015).


    Inter-individual Differences in Genetically Modulated Opioid Response

    The study reviewed clinical studies involving the pharmacodynamics and pharmacokinetics of opioids. It examined the opioid agents morphine, codeine, tramadol, oxycodone, fentanyl, and hydrocodone and the relationship to single nucleotide polymorphisms (SNPs): OPRM1, COMT (specifically COMT Val Met), CYP2D6, CYP3A4/5, and ABCB1, which the study claimed are responsible for the inter-individual differences in opioid response.

    The authors specifically found that OPRM1, COMT Val Met, and ABCB1 are most strongly correlated with morphine response. One study combined OPRM1 and ABCB1 and found that patients with both of these genetic variants were the best responders as indicated in patients’ measures of pain intensity. In another study, patients with OPRM1 and COMT Val Met needed the lowest morphine dose compared to other genotypes. All three together demonstrated no difference in morphine dose requirements.


    CYP2D6 Variants Correlate with Drug Efficacy

    Similarly, the presence of CYP2D6 variants correlated positively with variations in codeine and tramadol efficacy. CYP2D6 is responsible in converting the analgesic properties of codeine and tramadol. In studies investigating codeine pharmacotherapy in cancer patients, analgesic differences and adverse effects were found for CYP2D6 poor, intermediate, and extensive metabolizers.

    The authors concluded CYP2D6 testing helps in finding which patients respond positively to codeine. Studies with tramadol focusing on non-cancer pain populations identified CYP2D6 poor metabolizers as having a decreased analgesic response compared to extensive metabolizers. However, the authors noted there has been no specific study relating to tramadol’s analgesic efficacy in cancer populations, arguing tramadol will likely have decreased clinical benefit in patients who are poor CYP2D6 metabolizers.


    Call for Preemptive Genotyping in Clinical Practice

    The authors assert that these findings “suggest genotyping patients for some of these genetic variants may help predict responses to pain treatments with good rates of sensitivity and specificity and with greater benefits for patients and decreased health care utilization.” Furthermore, the authors assert that utilizing pharmacogenomics data combined with a preemptive genotyping be a “key element” in guiding treatment decisions for cancer patients.

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    Glipizide (Glucotrol) Uses and Side Effects

    By | Diabetes, Sulfonylureas | No Comments

    Glipizide is an antidiabetic drug of the chemical sulfonylurea class.  It is an oral and short acting drug that is classified as a second generation sulfonylurea.  It is marketed by Pfizer under the name Glucotrol in the United States. 

    How Does Glipizide Work?

    Like other sulfonylurea antidiabetic medicines, glipizide induces insulin release from pancreatic beta cells, but only when there is some beta-cell activity remaining in the pancreas.  This helps control blood sugar to maintain it at normal levels.  Glipizide is used with diet and exercise to have a healthy lifestyle with your type II diabetes diagnosis.  Some patients cannot take glipizide: If you have blockage in your intestines, kidney or liver disease, or a history of heart disease.  Tell your doctor if you have a glucose-6-phosphate deficiency (G6PD), a disorder of the pituitary or adrenal glands.

    Warnings and Side Effects

    Some oral diabetes drugs can increase your risk of serious heart issues.  Not taking your diabetes drugs have damage your heart and other organs, so you should talk to your physician about your risks. Other side effects of the sulfonylurea class of diabetes drugs include: low blood sugar symptoms such as dizziness, confusion, sweating, nervousness, weight gain, upset stomach, hunger, skin reactions, and dark urine.

    How Do Genetics Determine Drug Metabolism?

    Since the human genome was completed, many genome wide association studies have revealed that there are variations in the many genes that are responsible for processing drugs. processing in your body is also called drug metabolism.  Genes provide ‘instructions’ for the production of the actual enzymes responsible for drug metabolism.  Thus, variations in the genes transfer to the enzyme, which will have variations from the genetic instructions.  Variations in the enzyme may mean that the drug metabolism function is altered.  That could mean that the enzyme responsible for metabolizing several or a number of drugs isn’t working properly, resulting in side effects. 

    Genetic Testing with Rxight®

    One important way to know beforehand if you have any drug metabolism variations is to get the Rxight® pharmacogenetics test from MD Labs.  With one simple cheek swab, you and your physician can have at hand the results of this state-of-the-art platform that reveals your genetic disposition to any of the 200 drugs and over-the-counter products on the market.


    To avoid side effects or medication inefficacy, ask your physician to prescribe the Rxight® pharmacogenetics test from MD Labs.  All that is required is a participating pharmacy and your physician’s prescription.  It also brings precision medicine to you and your physician, utilizing more individualized medical care.