Sedation, usually transient, may occur during the initial period of therapy
or whenever the dose is increased. Headache, asthenia, or weakness may be noted
as early and transient symptoms. However, significant adverse effects due to
methyldopa have been infrequent and this agent usually is well tolerated. The
following adverse reactions have been reported and, within each category, are
listed in order of decreasing severity.
Cardiovascular: Aggravation of angina pectoris, congestive heart failure,
prolonged carotid sinus hypersensitivity, paradoxical pressor response with
intravenous use, orthostatic hypotension (decrease daily dosage), edema and
weight gain, bradycardia.
Digestive: Pancreatitis, colitis, vomiting, diarrhea, sialadenitis,
sore or "black" tongue, nausea, constipation, distension, flatus,
dryness of mouth.
Hematologic: Bone marrow depression, leukopenia, granulocytopenia, thrombocytopenia,
hemolytic anemia; positive tests for antinuclear antibody, LE cells, and rheumatoid
factor, positive Coombs tests.
Hepatic: Liver disorders including hepatitis, jaundice, abnormal liver
function test (see WARNINGS).
Hypersensitivity: Myocarditis, pericarditis, vasculitis, lupus-like syndrome, drug-related fever, eosinophilia.
Nervous System/Psychiatric: Parkinsonism, Bell's palsy, decreased mental
acuity, choreoathetotic movements, symptoms of cerebrovascular insufficiency,
psychic disturbances including nightmares and reversible mild psychoses or depression,
headache, sedation, asthenia or weakness, dizziness, lightheadedness, paresthesias.
Metabolic: Rise in BUN.
Musculoskeletal: Arthralgia, with or without joint swelling; myalgia.
Respiratory: Nasal stuffiness.
Skin: Toxic epidermal necrolysis, rash.
Urogenital: Amenorrhea, breast enlargement, gynecomastia, lactation,
impotence, decreased libido.