MedLibrary.org

Prescription Medications

Renese-R

RENESE-R- polythiazide and reserpine tablet
Pfizer Labs

WARNING

This fixed combination drug is not indicated for initial therapy of hypertension. Hypertension requires therapy titrated to the individual patient. If the fixed combination represents the dosage so determined, its use may be more convenient in patient management. The treatment of hypertension is not static, but must be reevaluated as conditions in each patient warrant.

DESCRIPTION

RENESE®-R tablets combine polythiazide and reserpine, two antihypertensive agents with complementary properties. Each blue, scored tablet of RENESE-R provides:

Renese (polythiazide). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 mg

Reserpine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . .0.25 mg

RENESE (polythiazide) is a member of the benzothiazide (thiazide) family of diuretic/antihypertensive agents. It is designated chemically as 2H-1,2,4-Benzothiadiazine-7-sulfonamide,6-chloro-3,4-dihydro-2-methyl-3-[[2,2,2-trifluoroethyl)thio]methyl]-,1,1-dioxide with a molecular formula of C11 H13 ClF3 N3 O4 S3 and a molecular weight of 439.87.

Polythiazide is a white crystalline substance insoluble in water, but readily soluble in alkaline solution, and has the following structural formula:

Image from Drug Label Content

Reserpine, one of the alkaloids of Rauwolfia serpentina , has the following structural formula:

Image from Drug Label Content
(click image for full-size original)

Reserpine – which is administered orally, is insoluble in water, very slightly soluble in ether, l g in about 1800 mL alcohol and about 6 mL chloroform, slightly soluble in benzene, freely soluble in acetic acid.

It has a molecular weight of 608.69 and its molecular formula is C33 H40 N2 O9 . Reserpine is chemically designated as Yohimban-16-carboxylic acid, 11,17-dimethoxy-18-[(3,4,5-trimethoxybenzoyl)oxy]-, methyl ester, (3β,16β,17α,18β,20α)-. It is a white or pale buff to slightly yellowish crystalline powder that is insoluble in water.

Inert Ingredients: FD&C Blue No. 1; dibasic calcium phosphate; lactose; magnesium stearate; polyethylene glycol; sodium lauryl sulfate; starch; vanillin.

CLINICAL PHARMACOLOGY

Polythiazide

Renese (polythiazide) alone has demonstrated clinical effectiveness in lowering elevated blood pressure in patients without visible edema as well as in edematous hypertensive patients. Its mechanism of action results in an interference with the renal tubular mechanism of electrolyte reabsorption. At maximal therapeutic dosage all thiazides are approximately equal in their diuretic potency. The mechanism whereby thiazides function in the control of hypertension is unknown. Polythiazide is well absorbed following oral administration with diuresis beginning approximately 2 hours later. Peak human plasma concentrations occur about 5 hours after ingestion. Polythiazide is removed slowly thereafter with a plasma elimination half-life of approximately 27 hours. One-fifth of the drug is recovered unchanged in human urine; the remainder is cleared via feces and as metabolites. Animal studies indicate metabolism occurs by rupture of the thiadiazine ring and loss of the side chain.

Reserpine

Reserpine has several complementary actions of benefit to the hypertensive patient, including a calming effect and a slowing of the pulse rate.

Depletion of norepinephrine from tissue receptor sites is thought to be responsible for the decrease in peripheral vascular resistance and subsequent fall in blood pressure. Bradycardia is usually associated with this effect.

The tranquilizing effect of reserpine is apparently due to serotonin and catecholamine depletion in the brain.

Sympathetic inhibition produced by reserpine also may result in vasodilation and increased cutaneous blood flow with resulting flushing, feeling of warmth, or nasal congestion. Increased parasympathomimetic activity may produce increased gastrointestinal motility, increased gastric acid secretion and miosis.

Reserpine is absorbed orally and is widely distributed in body tissues, especially adipose tissue. A study in a small number of normal subjects who received a radioactively labeled 0.25 mg dose of reserpine showed a biphasic half-life of 4.5 hours during the first phase, and 11.3 days during the second phase. The full therapeutic effects of reserpine may not be seen for 2–3 weeks.

Reserpine is extensively metabolized to inactive compounds. It is slowly excreted via the urine and feces.

Reserpine crosses the blood-brain barrier and the placenta, and appears in cord blood.

Since polythiazide reduces or eliminates the sodium and fluid retention frequently associated with hypertension, it enhances the efficacy of reserpine in lowering elevated blood pressure. RENESE-R often has been found to be more effective than equivalent doses of either agent alone. Both the cardiovascular and central nervous system effects may persist following withdrawal of the drug.

Renese-R Indications and Usage

Hypertension (see box warning).

Usage in Pregnancy

The routine use of diuretics in an otherwise healthy woman is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy, and there is no satisfactory evidence that they are useful in the treatment of developed toxemia.

Edema during pregnancy may arise from pathological causes or from the physiologic and mechanical consequences of pregnancy. Thiazides are indicated in pregnancy when edema is due to pathologic causes, just as they are in the absence of pregnancy (however, see Precautions/Pregnancy section). Dependent edema in pregnancy, resulting from restriction of venous return by the expanded uterus, is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is illogical and unnecessary. There is hypervolemia during normal pregnancy which is harmful to neither the fetus nor the mother (in the absence of cardiovascular disease), but which is associated with edema – including generalized edema, in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief. In rare instances, this edema may cause extreme discomfort which is not relieved by rest. In these cases, a short course of diuretics may provide relief and may be appropriate.

CONTRAINDICATIONS

A. Related to polythiazide

  1. Advanced renal or hepatic failure.
  2. Hypersensitivity to this or other sulfonamide derivatives.

B. Related to reserpine

  1. Demonstrated hypersensitivity.
  2. Patients with a history of mental depression.
  3. Demonstrated peptic ulcer or ulcerative colitis.

WARNINGS

Serum electrolyte determinations are especially indicated for patients with severe derangement of metabolic processes, e.g., surgery, vomiting, or parenteral fluid therapy. Electrolyte imbalance may be caused by certain diseases such as cirrhosis, or it may result from drug therapy, such as therapy with corticosteroids. Patients with cirrhosis who are continually receiving RENESE-R should be observed carefully for the development of hepatic precoma or coma. Indications of impending hepatic failure are tremor, confusion, drowsiness, and hepatic fetor.

Thiazides may precipitate kidney failure and uremia in patients with pre-existing renal pathology and impaired renal function.

Available information tends to implicate all oral dosage forms of potassium salts ingested in solid form with or without thiazides in the etiology of nonspecific, small bowel lesions consisting of ulceration with or without stenosis, causing obstruction, hemorrhage and perforation, and frequently requiring surgery. Deaths due to these complications have been reported. All oral dosage forms of potassium salts ingested in solid form should be used only when adequate dietary supplementation is not practical, and should be discontinued immediately if abdominal pain, distention, nausea, vomiting, or gastrointestinal bleeding occur.

RENESE-R does not itself contain enteric-coated potassium.

Electroshock therapy should not be given within one week of cessation of reserpine.

Reserpine may cause mental depression. Recognition of depression may be difficult because this condition may often be disguised by somatic complaints (Masked Depression). The drug should be discontinued at first signs of depression such as despondency, early morning insomnia, loss of appetite, impotence, or self-deprecation. Drug-induced depression may persist for several months after drug withdrawal and may be severe enough to result in suicide.

Page 1 of 3 1 2 3 »