The lowest reported acute lethal dose was 1 gram. If generic versions of this product have been approved by the FDA, there may be Symmetrel (Amantadine Hydrochloride, USP) is designated generically as amantadine hydrochloride and chemically as 1-adamantanamine hydrochloride.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 tablet intended for oral administration contains 100 mg amantadine hydrochloride and has the following inactive ingredients: hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, sodium starch glycolate, FD&C Yellow No. Alternatively, temporary discontinuation of Symmetrel for several weeks, followed by reinitiation of the drug, may result in regaining benefit in some patients. Select one or more newsletters to continue. Central nervous system effects that have been reported include insomnia, anxiety, agitation, aggressive behavior, hypertonia, hyperkinesia, ataxia, gait abnormality, tremor, confusion, disorientation, depersonalization, fear, delirium, hallucinations, psychotic reactions, lethargy, somnolence and coma. is essential. Amantadine, after single oral 200 mg doses to 6 healthy young subjects and to 6 healthy elderly subjects has been found in nasal mucus at mean ± SD concentrations of 0.15 ± 0.16, 0.28 ± 0.26, and 0.39 ± 0.34 μg/g at 1, 4, and 8 hours after dosing, respectively. Venodilators, such as nitrates, decrea … Vasodilator therapy for acute myocardial infarction and chronic congestive heart failure J Am Coll Cardiol. However, such patients should be supervised closely by their physicians.Patients initially deriving benefit from Symmetrel not uncommonly experience a fall-off of effectiveness after a few months. If Symmetrel is used chemoprophylactically in conjunction with inactivated influenza A virus vaccine until protective antibody responses develop, then it should be administered for 2 to 4 weeks after the vaccine has been given. A number of factors have limited the widespread application of hydralazine–isosorbide dinitrate to patients with HF. 1983 Jan;1(1):133-53. doi: 10.1016/s0735-1097(83)80018-7. Excipient (s) with Known effect For the full list of excipients, see section 6.1. (M.S., M.W. Supportive measures including intravenous fluids are also indicated. In return for equity and potential future royalties, NitroMed licensed from him the patent for mortality reduction of the drug combination in heart failure. Following vaccination during an influenza A outbreak, Symmetrel prophylaxis should be considered for the 2- to 4-week time period required to develop an antibody response.Symmetrel is 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. Across other studies, amantadine plasma half-life has averaged 16 ± 6 hours (range: 9 to 31 hours) in 19 healthy volunteers.After oral administration of a single dose of 100 mg amantadine syrup to five healthy volunteers, the mean ± SD maximum plasma concentration CPlasma amantadine clearance ranged from 0.2 to 0.3 L/hr/kg after the administration of 5 mg to 25 mg intravenous doses of amantadine to 15 healthy volunteers.In six healthy volunteers, the ratio of amantadine renal clearance to apparent oral plasma clearance was 0.79 ± 0.17 (mean ± SD).The volume of distribution determined after the intravenous administration of amantadine to 15 healthy subjects was 3 to 8 L/kg, suggesting tissue binding. ); Veterans Affairs Medical Center, Washington, D.C. A heterogeneous population may have substantial variations in genetic and environmental factors that influence disease progression and the response to therapy. Patients who attempt suicide may exhibit abnormal mental states which include disorientation, confusion, depression, personality changes, agitation, aggressive behavior, hallucinations, paranoia, other psychotic reactions, and somnolence or insomnia. Tetralogy of Fallot and tibial hemimelia (normal karyotype) occurred in an infant exposed to amantadine during the first trimester of pregnancy (100 mg P.O.