Neurological
Side effects include drowsiness (especially while driving), lightheadedness, falls, and dizziness. Patients on amantadine should avoid combination with other central nervous system (CNS) depressing agents, such as alcohol. Excessive alcohol usage may increase the potential for CNS effects such as dizziness, confusion, and light headedness.Rare severe adverse effects include neuroleptic malignant syndrome, depression, convulsions, psychosis, and suicidal ideation. It has also been associated with disinhibited actions (gambling, sexual activity, spending, other addictions) and diminished control over compulsions. Cardiovascular
Amantadine may cause orthostatic hypotension, syncope, and peripheral edema. Gastrointestinal
Amantadine has also been associated with dry mouth and constipation. Skin
Rare cases of skin rashes, such as Stevens–Johnson syndrome and livedo reticularis have also been reported in patients treated with amantadine. Pregnancy and lactation
Amantadine is Food and Drug Administration category C for pregnancy. Teratogenic effects have been observed in humans (case reports) and animal reproduction studies. Amantadine may also be present in breast milk and negatively alter breast milk production or excretion. The decision to breastfeed during amantadine therapy should consider the risk of infant exposure, the benefits of breastfeeding, and the benefits of the drug to the mother. Interactions
Amantadine may affect the central nervous system due to dopaminergic and anticholinergic properties. The mechanisms of action are not fully known. Because of the CNS effects, caution is required when prescribing additional CNS stimulants or anticholinergic drugs. Thus, concurrent use of alcohol with Amantadine is not recommended due to enhanced CNS depressant effects. In addition, anti-dopaminergic drugs such as metoclopramide and typical anti-psychotics should be avoided.
Anal fistula is a chronic abnormal communication between the epithelialised surface of the anal canal and usually the perianal skin. An anal fistula can be described as a narrow tunnel with its internal opening in the anal canal and its external opening in the skin near the anus. Anal fistulae commonly occur in people with a history of anal abscesses. They can form when anal abscesses do not heal properly.Anal fistulae originate from the anal glands, which are located between the internal and external anal sphincter and drain into the anal canal. If the outlet of these glands becomes blocked, an abscess can form which can eventually extend to the skin surface. The tract formed by this process is a fistula.Abscesses can recur if the fistula seals over, allowing the accumulation of pus. It can then extend to the surface again – repeating the process.Anal fistulae per se do not generally harm, but can be very painful, and can be irritating because of the drainage of pus (it is also possible for formed stools to be passed through the fistula). Additionally, recurrent abscesses may lead to significant short term morbidity from pain and, importantly, create a starting point for systemic infection.Treatment, in the form of surgery, is considered essential to allow drainage and prevent infection. Repair of the fistula itself is considered an elective procedure which many patients opt for due to the discomfort and inconvenience associated with an actively draining fistula.