Dosing and uses of Mecamylamine
Adult dosage forms and strengths
tablet
- 2.5mg
Hypertension
Indicated for moderately severe-to-severe essential hypertension and uncomplicated malignant hypertension
2.5 mg PO BID intially; may increase by 2.5 mg increments at interval not less than 2 days
Average total daily dose is 25 mg (in 3 divided doses); however, as little as 2.5 mg/day may be sufficient
Administration
Take after meals; may cause more gradual absorption and smoother control of excessively high blood pressure
Pediatric dosage forms and strengths
Safety and efficacy not established
Mecamylamine adverse (side) effects
Frequency not defined
Common
- Orthostatic hypotension
- Dizziness, lightheadedness
- Fatigue
- Sedation
- Constipation
- Dry mouth
- Nausea/Vomiting
- Xerostomia
Serious
- Syncope
- Seizure
- Tremor
- Paralytic ileus
- Chorea
- Dysuria
Warnings
Contraindications
Hypersensitivity to mecamylamine
Coronary insufficiency, glaucoma, recent MI, pyloric stenosis, renal insufficiency, uremia
Do not use w/antibiotics, sulfonamides
Cautions
Arteriosclerosis, bladder neck obstruction, urethral stricture, cerebral insufficiency, gastrointestinal obstruction, prostatic hypertrophy
Potentiation of hypotensive effects due to excessive heat, fever, infection, hemorrhage, pregnancy, anesthesia, alcohol consumption, salt depletion, or diarrhea
Avoid abrupt withdrawaL
Rarely used
Pregnancy and lactation
Pregnancy category: C
Lactation: may cross into the breast milk, use caution
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Mecamylamine
Mechanism of action
Ganglionic blocker, inhibits acetylcholine at autonomic ganglia resulting in decreased blood pressure
Pharmacokinetics
Half-Life: 24 hr
Onset: 0.5-2 hr
Duration: 6-12 hr
Excretion: urine 100%
