Hydrochlorothiazide – Reserpine
Diuretic – Antihypertensive
Indications And Clinical Uses: Fixed-dose combination drugs are not indicated for initial therapy. Patients should be titrated on the individual drugs. If the fixed combination represents the dosage so determined, its use may be more convenient in patient management. If during maintenance therapy dosage adjustment is necessary it is advisable to use the individual drugs.
In many cases of hypertension, Hydropres-25 alone may control the blood pressure. If a greater antihypertensive effect is required, more potent drugs can be added in comparatively small dosage and with smoother control.
Contra-Indications: All diuretics, including hydrochlorothiazide, are contraindicated in anuria. If increasing azotemia and oliguria occur during treatment of severe progressive renal disease, Hydropres-25 should be discontinued. Electroshock therapy should not be given to patients while on reserpine, as severe and even fatal reactions have been reported with minimal convulsive electroshock dosage. At least 7 days should elapse between discontinuance of reserpine and initiation of electroshock therapy. Hydropres-25 is contraindicated in persons known to be sensitive to hydrochlorothiazide or to other sulfonamide-derived drugs or to reserpine. This combination is contraindicated, because of its reserpine content, in active peptic ulcer, in ulcerative colitis, and in active mental depression, especially with suicidal tendencies. See also Pregnancy and Lactation under Warnings.
Manufacturers’ Warnings In Clinical States: Azotemia may be precipitated or increased by hydrochlorothiazide. Cumulative effects of the drug may develop in patients with impaired renal function. If increasing azotemia and oliguria occur during treatment of severe progressive renal disease Hydropres-25 should be discontinued.
Thiazides should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance, or of serum ammonia, may precipitate hepatic coma.
Sensitivity reactions may occur in patients with or without a history of allergy or bronchial asthma.
Hydrochlorothiazide adds to or potentiates the action of other antihypertensive drugs. Potentiation occurs with ganglionic or peripheral adrenergic blocking drugs.
The possibility of exacerbation or activation of systemic lupus erythematosus has been reported for sulfonamide derivatives (including thiazides), and reserpine.
The occurrence of mental depression due to reserpine in doses of 0.25 mg daily or less is unusual. In any event, Hydropres-25 should be discontinued at the first sign of depression.
Nonspecific small bowel lesions consisting of stenosis with or without ulceration, may occur in association with the administration of enteric coated potassium salts, alone or with oral diuretics. These small bowel lesions have caused obstruction, hemorrhage and perforation. Surgery was frequently required and deaths have occurred. Available information tends to implicate enteric coated potassium salts, although lesions of this type also occur spontaneously. Such preparations should be used only when adequate dietary supplementation is not practical, and should be discontinued immediately if abdominal pain, distension, nausea, vomiting or gastrointestinal bleeding occur.
Pregnancy: Reserpine has been demonstrated to cross the placental barrier in guinea pigs with depression of adrenal catecholamine stores in the newborn. There is some evidence that side effects such as nasal congestion, lethargy, depressed Moro reflex, and bradycardia may appear in infants born of reserpine-treated mothers. Thiazides cross the placental barrier and appear in cord blood. When Hydropres-25 is used in pregnancy or in women of childbearing age, the potential benefits of the drug should be weighed against the possible hazards to the fetus. These hazards include fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions which have occurred in the adult.
Lactation: Since thiazides and reserpine appear in breast milk, Hydropres-25 is contraindicated in nursing mothers. If use of the drug is deemed essential, the patient should stop nursing.
Precautions: Since reserpine may increase gastric secretion and motility, it should be used cautiously in patients with a history of peptic ulcer, ulcerative colitis, or other gastrointestinal disorders. This compound may precipitate biliary colic in patients with gallstones, or bronchial asthma in susceptible persons.
Reserpine may cause hypotension including orthostatic hypotension. In hypertensive patients on reserpine therapy significant hypotension and bradycardia may develop during surgical anesthesia.
Therefore, Hydropres-25 should be discontinued two weeks before giving anesthesia. For emergency surgical procedures, it may be necessary to give vagal blocking agents parenterally to prevent or reverse hypotension and/or bradycardia.
Anxiety or depression, as well as psychosis, may develop during reserpine therapy. If depression is present when therapy is begun, it may be aggravated. Mental depression is unusual with reserpine doses of 0.25 mg daily or less. In any case, Hydropres-25 should be discontinued at the first sign of depression. Extreme caution should be used in treating patients with a history of mental depression, and the possibility of suicide should be kept in mind.
As with most antihypertensive therapy, caution should be exercised when treating hypertensive patients with renal insufficiency, since they adjust poorly to lowered blood pressure levels. Use reserpine cautiously with digitalis and quinidine; cardiac arrhythmias have occurred with reserpine preparations.
Careful check should be kept for signs of fluid and electrolyte imbalance, namely, hyponatremia, hypochloremic alkalosis, hypokalemia and hypomagnesemia. Serum and urine electrolyte determinations are particularly important when the patient is vomiting excessively or receiving parenteral fluids. Warning signs, irrespective of cause, are: dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia and gastrointestinal disturbances.
Hypokalemia may develop with hydrochlorothiazide as with any other potent diuretic, especially with brisk diuresis, when severe cirrhosis is present, or during concomitant steroid or ACTH administration. Interference with adequate electrolyte intake will contribute to hypokalemia. Hypokalemia can sensitize or exaggerate the response of the heart to the toxic effects of digitalis (e.g., increased ventricular irritability). Hypokalemia may be avoided or treated by giving foods with a high potassium content of if necessary by the use of potassium chloride.
Any chloride deficit is generally mild and usually does not require specific treatment except under extraordinary circumstances (as in liver disease or renal disease). Dilutional hyponatremia may occur in edematous patients in hot weather; appropriate therapy is water restriction, rather than administration of salt except in rare instances when the hyponatremia is life threatening. In actual salt depletion, appropriate replacement is the therapy of choice.
Thiazides may decrease serum PBI levels without signs of thyroid disturbance.
Calcium excretion is decreased by hydrochlorothiazide and magnesium excretion is increased.
Pathological changes in the parathyroid glands with hypercalcemia and hypophosphatemia have been observed in a few patients on prolonged thiazide therapy. The common complications of hyperparathyroidism such as renal lithiasis, bone resorption, and peptic ulceration have not been seen. Thiazides should be discontinued before carrying out tests for parathyroid function.
Hyperuricemia may occur or gout may be precipitated.
Patients should be observed regularly for the possible occurrence of liver dysfunction, idiosyncratic reactions, or blood dyscrasias.
Sensitivity reactions to thiazides may occur in patients with or without a history of allergy or bronchial asthma.
The possibility of exacerbation or activation of systemic lupus erythematosus has been reported with the thiazides.
Insulin requirements in diabetic patients may be increased, decreased or unchanged. Diabetes mellitus which has been latent may become manifest during thiazide administration.
Drug Interactions: Hydrochlorothiazide potentiates the action of other antihypertensive drugs. Therefore, the dosage of these agents, especially the ganglion blockers, may need to be reduced when Hydropres-25 is added to the regimen.
Lithium should generally not be given to patients receiving diuretics, since the risk of lithium toxicity is very high in such patients.
Thiazide-containing drugs may increase the responsiveness to tubocurarine. The antihypertensive effect of the drug may be enhanced in the postsympathectomy patient.
Hydrochlorothiazide may decrease arterial responsiveness to norepinephrine. This diminution is not sufficient to preclude the effectiveness of the pressor agent for therapeutic use.
Orthostatic hypotension may occur and may be potentiated by alcohol, barbiturates, or narcotics.
Adverse Reactions: Reserpine: The reactions most often reported include: excessive sedation, nightmares, nasal congestion, conjunctival injection, enhanced susceptibility to colds, muscular aches, headache, dizziness, dyspnea, anorexia, nausea, increased intestinal motility, diarrhea, weight gain, dryness of the mouth, blurred vision, flushing of the skin and pruritus. Skin rash, dysuria, syncope, nonpuerperal lactation, impotence or decreased libido, increased salivation, vomiting, bradycardia, mental depression, nervousness, paradoxical anxiety, epistaxis, excessive bleeding following prostatic surgery, purpura due to thrombocytopenia, angina pectoris and other direct cardiac effects (e.g., premature ventricular contractions, fluid retention, congestive failure), and CNS sensitization, manifested by dull sensorium, deafness, glaucoma, uveitis, and optic atrophy also have been noted. In some patients reserpine has produced a syndrome similar to Parkinson’s Disease, though this effect usually is reversible with decreased dosage or discontinuance of therapy. Hydropres-25 should be given with caution to hypertensive patients who have also coronary artery disease to avoid a precipitous drop in blood pressure. Side effects due to reserpine may disappear with continued use and in many cases can be controlled by reducing the dosage. Rarely, it may be necessary to discontinue therapy.
Hydrochlorothiazide: Gastrointestinal: anorexia, gastric irritation, nausea, vomiting, cramping, diarrhea, constipation, jaundice (intrahepatic cholestatic jaundice), pancreatitis, sialadenitis.
CNS: dizziness, vertigo, paresthesias, headache, xanthopsia.
Hematologic: leukopenia, agranulocytosis, thrombocytopenia, aplastic anemia, hemolytic anemia.
Cardiovascular: orthostatic hypotension (may be aggravated by alcohol, barbiturates or narcotics).
Hypersensitivity: purpura, photosensitivity, rash, urticaria, necrotizing angiitis (vasculitis) (cutaneous vasculitis), fever, respiratory distress, including pneumonitis, anaphylactic reactions.
Other: hyperglycemia, glycosuria, hyperuricemia, muscle spasm, weakness, restlessness, transient blurred vision.
Whenever adverse reactions are moderate or severe, thiazide dosage should be reduced or therapy withdrawn.
Symptoms And Treatment Of Overdose: Symptoms: Reserpine: Impairment of consciousness may occur and may range from drowsiness to coma, depending upon the severity of overdosage. Flushing of the skin, conjunctival injection, and pupillary constriction are to be expected. Hypotension, hypothermia, central respiratory depression and bradycardia may develop in cases of severe overdosage. Diarrhea may also occur.
Hydrochlorothiazide: Overdosage may lead to excessive diuresis with electrolyte depletion (hypokalemia, hypochloremia, hyponatremia) and dehydration.
Signs are dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, gastrointestinal disturbances, mental confusion, delirium, convulsions, shock, coma.
If digitalis has also been administered, hypokalemia may accentuate myocardial abnormalities (e.g., cardiac arrhythmias).
Hydrochlorothiazide may precipitate hepatic coma in cirrhotics, potentiate other antihypertensive agents, and decrease responsiveness to norepinephrine.
Treatment: There is no specific antidote. Treatment is symptomatic and supportive.
Evacuate stomach contents, taking adequate precautions against aspiration and for the protection of the airway, instill activated charcoal slurry.
Correct dehydration, electrolyte imbalance, hepatic coma, by established procedures. Administer oxygen or artificial respiration for respiratory impairment.
If hypotension is severe enough to require treatment with a vasopressor, use one having a direct action upon vascular smooth muscle (e.g., phenylephrine, levarterenol). If bradycardia becomes marked, especially with cardiac arrhythmias, consider the use of vagal blocking agents along with other appropriate measures. Since reserpine is long acting, watch the patient carefully for at least 72 hours, administering treatment as required.
Dosage: Adults: 1 tablet 1 to 4 times a day; Within this range, the dosage is increased or decreased according to the blood pressure response of the patient.
Availability And Storage: Each green, flat, compressed tablet with a beveled edge, scored on one side with MSD symbol on the other contains: hydrochlorothiazide 25 mg and reserpine 125 g. Also contains lactose. Gluten- and tartrazine-free. Bottles of 100. (Shown in Product Recognition Section)
HYDROPRES®-25 MSD Hydrochlorothiazide – Reserpine Diuretic – Antihypertensive
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