Ismelin Dosage

Generic name: guanethidine monosulfate
Dosage form: Tablets

The information at Drugs.com is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.

Better control may be obtained, especially in the initial phases of treatment, if the patient can have his blood pressure recorded regularly at home.

Ambulatory Patients

Initial doses should be small (10 mg) and increased gradually, depending upon the patient's response. Ismelin has a long duration of action; therefore, dosage increases should not be made more often than every 5-7 days, unless the patient is hospitalized.

Blood pressure should be measured in the supine position, after standing for 10 minutes, and immediately after exercise if feasible. Dosage may be increased only if there has been no decrease in the standing blood pressure from previous levels. The average daily dose is 25-50 mg; only one dose a day is usually required.

Dosage Chart for Ambulatory Patients

Visits (intervals of 5 - 7 Days)                                    Daily Dose

Visit 1 (Patient may be started on 10-mg tablets)............................................................ 10 mg

Visit 2 ...............................................................................................................................20 mg

Visit 3 (Patient may be changed to 25-mg tablets whenever convenient)....................... 30 mg (three 10-mg tablets) or 37.5 mg (one and one-half 25-mg tablets)

Visit 4 .............................................................................................................................. 50 mg

Visit 5 and subsequent........................... Dosage may be increased by 12.5 mg or 25 mg if necessary.

The dosage should be reduced in any of the following situations: (1) normal supine pressure: (2) excessive orthostatic fall in pressure; (3) severe diarrhea.

Hospitalized Patients

Initial oral dose is 25-50 mg, increased by 25 mg or 50 mg daily or every other day, as indicated. This higher dosage is possible because hospitalized patients can be watched carefully. Unless absolutely impossible, the standing blood pressure should be measured regularly. Patients should not be discharged from the hospital until the effect of the drug on the standing blood pressure is known. Patients should be told about the possibility of orthostatic hypotension and warned not to get out of bed without help during the period of dosage adjustment.

Combination Therapy

Ismelin may be added gradually to thiazides and/or hydralazine. Thiazide diuretics enhance the effectiveness of Ismelin and may reduce the incidence of edema. When thiazide diuretics are added to the regimen in patients taking Ismelin, it is usually necessary to reduce the dosage of Ismelin. After control is established, the dosage of all drugs should be reduced to the lowest effective level.

Note: When Ismelin is replacing MAO inhibitors, at least 1 week should elapse before commencing treatment with Ismelin (see CONTRAINDICATIONS). If ganglionic blockers have not been discontinued before Ismelin is started, they should be gradually withdrawn to prevent a spiking blood pressure response during the transfer period.

Hide
(web5)