AMANTADINE
Generic Name: Amantadine
Brand Name: SYMMETREL
INTRODUCTION
Amantadine is antiviral and antiparkinonism drug.
INDICATIONS
FDA Approved for:
• Parkinson’s disease
• Influenza A infection
Off label uses:
• ADHD
• Chronic hepatitis C
DOSAGE
• 200 mg per day
Preparations:
• Tablets: 100 mg
• Oral solution: 50 mg/5 ml (480-ml)
PHARMACOLOGICAL ACTIONS
Mechanism of Action:
• It prevents the release of infectious viral nucleic acid into the host cell by interfering with the function of the transmembrane domain of the viral M2 protein.
• It may have direct and indirect effects on dopamine neurons.
• It is a weak, non-competitive NMDA receptor antagonist
Pharmacokinetics:
It is primarily excreted unchanged in the urine and has half life of 10 to 31 hours.
ADVERSE DRUG REACTIONS
Notable Side Effects
• Nausea
• Dizziness, insomnia
• Anxiety, depression
• Livedo reticularis
Life-Threatening Effects
• Congestive heart failure
• Psychosis
• Rare seizures
• Neuroleptic malignant syndrome
Drug Interactions:
• Agents with anticholinergic properties may potentiate the anticholinergic-like side effects of amantadine.
• Coadministration of thioridazine has been reported to worsen the tremor in elderly patients with Parkinson’s disease
• Coadministration of quinine or quinidine with amantadine was shown to reduce the renal clearance of amantadine by about 30%
LAB TESTS NEEDED
CPK, BUN, serum creatinine, LDH, liver function test.
CONTRAINDICATIONS
• If there is a proven hypersensitivity to amantadine
OVERDOSE
• Acute toxicity may be attributable to the anticholinergic effects of amantadine. Drug overdose has resulted in cardiac, respiratory, renal or central nervous system toxicity
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...s, delirium, anxiety, cardiac and respiratory arrest and even coma.
TAPERING AND WITHDRAWAL
It should be tapered gradually since sudden discontinuation results in withdrawal symptoms as nasal congestion, abdominal symptoms, diarrhea, muscle aches and anxiety.
SPECIAL POPULATIONS
• Cardiac impairment: It should be used with caution.
• Elderly: It should be used with caution as susceptible to adverse effects.
• Children and adolescents: Safety and efficacy has not been established.
• Pregnancy: Risk category C ( no controlled studies in humans)
• Breast Feeding: there is no study done in nursing mothers.
PRECAUTIONS
Risk of angle closure glaucoma.
Risk of urinary retention related to urethroprostatic disorders.
CLINICAL GUIDELINES AND PEARLS
• It is a weak peripheral anticholinergic agent
It has some anti secretory, antispasmodic and mydriatic effects.
...clearance and volume of distribution of unbound drug increased after post menstrual age with an increase of 41% and 25% of mature values respectively. The terminal half life decreased with an increase in age. This could be accounted for by differences in body weight and increase in metabolising enzymes as the subjects mature. Ropivacaine metabolism occurs by 1st order kinetics to PPX. the fraction metabolised utilised PPX urinary amounts. Post menstrual age and body weight were required in the expression of clearance, only body weight was required for the expression of volume. Clearance of unbound PPX achieved half of its mature value at 46.5 weeks post menstrual age. There was an increase of fraction metabolised in coloured and mixed race groups aged less than 1 year. The effects of increased volume and clearance are minimal as the metabolite in excreted anyway.
Goldmann, David R., and David A. Horowitz. American College of Physicians Home Medical Guide to Parkinson's Disease. New York: Dorling Kindersley Pub., 2000. Print.
Its ability to inhibit sodium channels within brain cells thereby protecting the cells from hypoxia (lack of oxygen)
"Aspirin for Reducing Your Risk of Heart Attack and Stroke: Know the Facts." Fda.gov. U.S. Food
But often the symptoms do not stop at acute withdrawal. After the body makes initial adjustments to the absence of drugs, the changes that have occurred in the brain still need time to revert back to their original state. During this period, a variety of symptoms known as Post-Acute Withdrawal Syndrome (PAWS) begin to occur. In the book Uppers, Downers, All Arounders, published by CNS Productions, authors Darryl Inaba and William Cohen define PAWS as “a group of emotional and physical symptoms that appear after major withdrawal symptoms have abated” (Inaba & Cohen, 2011).
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Parkinson disease (PD), also referred to as Parkinson’s disease and paralysis agitans, is a progressive neurodegenerative disease that is the third most common neurologic disorder of older adults. It is a debilitating disease affecting motor ability and is characterized by four cardinal symptoms: tremor rigidity, bradykinesia or kinesis (slow movement/no movement), and postural instability. Most people have primary, or idiopathic, disease. A few patients have secondary parkinsonian symptoms from conditions such as brain tumors and certain anti-psychotic drugs.
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What would you give to rid yourself of acne? What would you do? The bane of every adolescent’s existence, these red spots develop to some degree in 85% of the population between ages 12 and 25 (Lamberg). Teenagers wake up every morning, look at the mirror, and sigh at the acne on their faces and often other places on their bodies. They dread these awful things that are absolutely ugly. They get desperate and eventually, if the acne grows worse than ever before, they resort to Accutane. Accutane, also known as isotretinoin, is a medication for acne. However, despite isotretinoin’s helpfulness in controlling acne that is unresponsive to other treatments, this medication should not be used because of its harmful physical side effects, its association with psychiatric adverse effects, and its effects on reproduction.
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Acromegaly and gigantism are due to overproduction of Growth hormone (GH) usually caused by a GH-secreting pituitary adenoma— a disorder of unequal skeletal, tissue, and organ growth. The incidence of acromegaly is 5 cases per million per year and the prevalence is 60 cases per million. High GH and insulin-like growth factor-I (IGF1) levels lead to comorbidities including arthritis, facial changes, hypertension, diabetes mellitus, and heart and respiratory failure. If the condition is not diagnosed and treated early, its disabling effects leads to increase in morbidity and reduced life expectancy. The diagnosis is based on clinical features and confirmed by measuring growth hormone levels after oral glucose tolerance test and the estimation