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Mecamylamine Dosage

Medically reviewed by Last updated on Dec 2, 2022.

Applies to the following strengths: 2.5 mg

Usual Adult Dose for Hypertension

2.5 mg orally twice a day; may increase by one 2.5 mg tablet at intervals of 2 days or more until desired blood pressure response is achieved.


  • The average total daily dose is 25 mg, usually in 3 divided doses; however, 2.5 mg daily may be sufficient. Partial tolerance may develop in certain patients, which requires an increase in the total daily dose.
  • Four or more doses may be required when smooth control is difficult to obtain.
  • Titration should be determined by blood pressure readings in the erect position at the time of maximal effect of this drug, as well as by signs and symptoms of orthostatic hypotension. In severe or urgent cases, titration at larger increments and shorter intervals may be needed.

Use: Management of moderately severe to severe essential hypertension and uncomplicated cases of malignant hypertension.

Renal Dose Adjustments

No specific guidelines have been suggested. Caution is recommended; use with great discretion, if at all, when renal insufficiency is manifested by rising or elevated BUN; contraindicated in uremia.

Liver Dose Adjustments

Data not available

Dose Adjustments

Concomitant Use of a Thiazide Diuretic:

  • Decrease dose by 50% (continue thiazide diuretic at its usual dose)


Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.


Data not available

Other Comments

Administration advice: Post-meal administration may allow for more gradual absorption and smoother control of excessively high blood pressure. Administration in relation to meals should be consistent. Larger doses should be given at noon and perhaps in the evening. The morning dose should be relatively small and in some cases may be omitted.

Monitoring: Monitor blood pressure; measure in the erect position before initiation and with dose increases.

Patient advice:

  • Instructions may be given to reduce or omit a dose if blood pressure readings fall below a designated level or if faintness or lightheadedness occurs. No change should be made without the knowledge of the physician.
  • Inform patients that this drug may cause dizziness, lightheadedness, or fainting, especially when standing up. This effect may be increased by alcohol, exercise, or hot weather. Standing up slowly may alleviate this effect.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.