Amantadine hydrochloride Dosage Form: Medically reviewed on June 1, Amantadine hydrochloride is designated chemically as 1-adamantanamine hydrochloride. Its molecular weight is It has the following structural formula:. Amantadine hydrochloride is a stable white or nearly white crystalline powder, freely soluble in water and soluble in alcohol and in chloroform.
Amantadine hydrochloride has pharmacological actions as both an anti-Parkinson and an antiviral drug. Each capsule also contains the following inactive ingredients: The capsule shell contains the following: The imprinting ink contains the following: The mechanism by which Amantadine exerts its antiviral activity is not clearly understood.
It appears to mainly prevent the release of infectious viral nucleic acid into the host cell by interfering with the function of the transmembrane domain ventolin and pregnancy the viral M2 vinigar and diabetes. In certain cases, Amantadine is also known to prevent virus assembly during virus replication.
It does not appear to interfere with the immunogenicity of inactivated influenza A virus vaccine. Amantadine inhibits the replication of influenza A virus isolates from each of the subtypes, i, amantadine and anesthesia.
It has very little or no activity against influenza B virus isolates. Data from earlier animal studies suggest that Amantadine may have direct and indirect effects on dopamine neurons. Although Amantadine has not been shown to possess direct anticholinergic activity in animal studies, clinically, amantadine and anesthesia, it exhibits anticholinergic-like side effects such as dry mouth, urinary retention, and constipation, amantadine and anesthesia. Amantadine is well absorbed orally.
It is primarily excreted unchanged in the urine by glomerular filtration and tubular secretion. Eight metabolites of Amantadine have been identified in human urine. AcetylAmantadine was not amantadine and anesthesia in the plasma of the remaining seven amantadine and anesthesia. The contribution of this metabolite to efficacy or toxicity is not known. There appears to be a relationship between plasma Amantadine and anesthesia concentrations and toxicity.
As concentration increases, toxicity seems to be more prevalent, amantadine and anesthesia, however, absolute values of Amantadine concentrations associated with adverse effects have not been fully defined. Amantadine pharmacokinetics were determined in 24 normal adult male volunteers after the oral administration of a single Amantadine hydrochloride mg soft gel capsule, amantadine and anesthesia.
The time to peak concentration was 3. The apparent oral clearance was 0. After 15 days of Amantadine mg b. Plasma Amantadine clearance ranged from 0. In six healthy volunteers, the ratio of Amantadine renal clearance to apparent oral plasma clearance was 0. The apparent oral plasma clearance of Amantadine is reduced and the plasma half-life and plasma concentrations are increased in amantadine and anesthesia elderly individuals age 60 and older.
After single dose administration of 25 to 75 mg to 7 healthy, elderly male volunteers, amantadine and anesthesia, the apparent plasma clearance of Amantadine was 0. Whether these changes are due to decline in renal function or other age related factors is not known. Compared with otherwise healthy adult individuals, the clearance of Amantadine and anesthesia is significantly reduced in adult patients with renal insufficiency.
Amantadine is removed in negligible amounts by hemodialysis. The pH of the urine has been reported to influence the excretion rate of Amantadine. Since the excretion rate of Amantadine increases rapidly when the urine is acidic, the administration of urine acidifying drugs may increase the elimination of the drug from the body.
Amantadine hydrochloride capsules, USP are indicated for the prophylaxis and treatment of signs and symptoms of infection caused by various strains of influenza A virus. Amantadine hydrochloride capsules, USP are also indicated in the treatment of parkinsonism and drug-induced extrapyramidal reactions. Amantadine hydrochloride capsules are indicated for chemoprophylaxis against signs and symptoms of influenza A virus infection.
Because Amantadine does not completely prevent the host immune response to influenza A infection, individuals who take this drug may still develop immune responses to natural disease or vaccination and may be protected when later exposed to antigenically related viruses.
Following vaccination during an influenza A outbreak, Amantadine prophylaxis should be considered for the 2- to 4-week time period required to develop an antibody response.
Amantadine hydrochloride capsules amantadine and anesthesia also indicated in the treatment of uncomplicated respiratory tract illness caused by influenza A virus strains especially when administered early in the course of illness. There are no well-controlled clinical studies demonstrating that treatment with Amantadine hydrochloride capsules will avoid the development of influenza A amantadine and anesthesia pneumonitis or other complications in high risk patients.
There is no clinical evidence indicating that Amantadine hydrochloride capsules are effective in the prophylaxis or treatment of viral respiratory tract illnesses other than those caused by influenza A virus strains. The following points should be considered before initiating treatment or prophylaxis with Amantadine hydrochloride capsules.
It is indicated in those elderly patients believed to develop parkinsonism in association amantadine and anesthesia cerebral arteriosclerosis, amantadine and anesthesia. Amantadine hydrochloride is indicated in the treatment of drug-induced extrapyramidal reactions. Although anticholinergic-type side effects have been noted with Amantadine when used in patients with drug-induced extrapyramidal reactions, there is a lower incidence of these side effects than that observed amantadine and anesthesia the anticholinergic antiparkinson drugs.
Amantadine hydrochloride capsules, USP are contraindicated in patients with known hypersensitivity to Amantadine hydrochloride or to any of the other ingredients in Amantadine hydrochloride capsules, USP. Deaths have been reported from overdose with Amantadine. The lowest reported acute lethal dose was 1 gram. Acute toxicity may be attributable to the anticholinergic effects of Amantadine. Drug overdose amantadine and anesthesia resulted in cardiac, respiratory, renal or central nervous system toxicity, amantadine and anesthesia.
Suicide attempts, some of which have been fatal, have been reported in patients treated with Amantadine, many of whom received short courses for influenza treatment or prophylaxis. The incidence of suicide attempts is not known and the pathophysiologic mechanism is not understood. Suicide attempts and suicidal ideation have been reported in patients with and without prior history of psychiatric illness.
Amantadine can exacerbate mental problems in patients with a history of psychiatric disorders or substance abuse. Patients who attempt suicide may exhibit abnormal mental states which include disorientation, confusion, depression, personality changes, agitation, aggressive behavior, hallucinations, paranoia, amantadine and anesthesia, other psychotic reactions and somnolence or insomnia.
Because of the possibility of serious adverse effects, caution should be observed when prescribing Amantadine hydrochloride capsules to patients being treated with drugs having CNS effects, or for whom the potential risks outweigh the benefit of treatment. Patients with a history of epilepsy or other "seizures" should be observed closely for possible increased seizure activity.
Patients receiving Amantadine hydrochloride capsules who note central nervous system effects or blurring of vision should be cautioned against driving or working in situations where alertness and adequate motor coordination are important. Patients with a history of congestive heart failure or peripheral edema should be followed closely as there are patients who developed congestive heart failure while receiving Amantadine hydrochloride capsules.
Because Amantadine Hydrochloride Capsules, USP has anticholinergic effects and may cause mydriasis, it should not be given to patients with untreated angle closure glaucoma.
Amantadine and anesthesia dose of anticholinergic drugs or of Amantadine should be reduced if atropine-like effects appear when these drugs are used concurrently. Abrupt discontinuation may also precipitate delirium, agitation, delusions, hallucinations, paranoid reaction, stupor, anxiety, depression and slurred speech. Sporadic cases of possible Neuroleptic Malignant Syndrome NMS have been reported in association with dose reduction or withdrawal of Whats worse human or animal diabetes therapy.
Therefore, patients should be observed carefully when the dosage of Amantadine is reduced abruptly or discontinued, especially if the patient is receiving neuroleptics. NMS is an uncommon but life-threatening syndrome characterized by fever or hyperthermia; neurologic findings including muscle rigidity, involuntary movements, altered consciousness; mental status changes; other disturbances such as autonomic dysfunction, amantadine and anesthesia, tachycardia, tachypnea, hyper- or hypotension; laboratory findings such as creatine phosphokinase elevation, leukocytosis, myoglobinuria, and increased serum myoglobin, amantadine and anesthesia.
The early diagnosis of this condition is important for the appropriate management of these patients. Considering NMS as a possible diagnosis and ruling out amantadine and anesthesia acute illnesses e.
This may be especially complex if the clinical presentation includes both serious medical illness and untreated or inadequately treated extrapyramidal signs and symptoms EPS. Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, drug fever and primary amantadine and anesthesia nervous system CNS pathology. The management of NMS should include: Dopamine agonists, such as bromocriptine, and muscle relaxants, such as amantadine and anesthesia are often used in the treatment of NMS, however, their effectiveness has not been demonstrated in controlled studies.
Because Amantadine is mainly excreted in the urine, it accumulates in the plasma and in the body when renal function declines.
Dosage for Impaired Renal Function. Care should be exercised when administering Amantadine to patients with liver disease. Rare instances of reversible elevation of liver enzymes have been reported in patients receiving Amantadine, though a specific relationship between the drug and such changes has not been established. Postmarketing reports suggest that patients treated with anti-Parkinson medications can experience intense urges to gamble, increased sexual urges, intense urges to spend money uncontrollably, and other intense urges.
In some cases, although not all, these pulmonary embolism and breast cancer were reported to have stopped when the dose was reduced or the medication was discontinued.
Because patients may not recognize these behaviors as abnormal it is important for prescribers to specifically ask patients or their caregivers about the development of new or increased gambling urges, amantadine and anesthesia, sexual urges, uncontrolled spending or other urges while being treated with Amantadine hydrochloride. Physicians should consider dose reduction or stopping the medication if a patient develops such urges while taking Amantadine hydrochloride.
Ideally, periodic skin examinations should be performed by appropriately amantadine and anesthesia individuals e. The dose of Amantadine may need careful adjustment in patients with congestive heart failure, peripheral edema, or orthostatic hypotension.
Care should be exercised when administering Amantadine to patients with a history of recurrent eczematoid rash, or to patients with psychosis or severe psychoneurosis not controlled by chemotherapeutic agents. Serious bacterial infections may begin with influenza-like symptoms or may coexist with or occur as complications during the course of influenza. Amantadine has not been shown to prevent such complications.
Avoid excessive alcohol usage, since it may increase the potential for CNS effects such as dizziness, confusion, light-headedness and orthostatic hypotension. Avoid getting up suddenly from a sitting or lying position. If dizziness or lightheadedness occurs, notify physician, amantadine and anesthesia.
Do not take more medication than prescribed because of the risk of overdose. If there is no amantadine and anesthesia in a few days, or if medication appears less effective after a few weeks, amantadine and anesthesia, discuss with a physician.
Seek medical attention immediately if it is suspected that an overdose of medication has been taken. Careful observation is required when Amantadine is administered concurrently with central nervous system stimulants. Agents with anticholinergic properties may potentiate the anticholinergic-like side effects of Amantadine. Coadministration of triamterene and hydrochlorothiazide capsules resulted in a higher plasma Amantadine concentration in a year-old amantadine and anesthesia receiving Amantadine hydrochloride capsules mg t.
The concurrent use of Amantadine with live attenuated influenza vaccine LAIV intranasal has not been evaluated.