Viskazide
Viskazide Medication Information:
Viskazide medication comes in several different strengths; click on the strength you need to view prices from pharmacies competing to earn your business.
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Viskazide 25mg/10mg
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Viskazide 50mg/10mg
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Pharmacology
Viskazide contains the antihypertensive activity of 2 agents: a beta-adrenergic receptor blocking agent (pindolol) and a diuretic (hydrochlorothiazide).
Pindolol is a nonselective beta-adrenergic receptor blocking agent which possesses partial agonist activity (intrinsic sympathomimetic activity-ISA).
The mechanism of the antihypertensive effect of beta-adrenergic receptor blocking agents has not been established. Among the factors that may be involved are: (a) competitive ability to antagonize catecholamine induced tachycardia at the beta-receptor sites in the heart, thus decreasing cardiac output; (b) a reduction in total peripheral resistance; (c) inhibition of the vasomotor centres; (d) inhibition of renin release by the kidneys.
Hydrochlorothiazide increases excretion of sodium and chloride in approximately equivalent amounts, and may cause a simultaneous, usually minimal, loss of bicarbonate. Natriuresis is usually accompanied by some loss of potassium. The mechanism of the antihypertensive effect of thiazides may be related to the excretion and redistribution of body sodium. Hydrochlorothiazide usually does not decrease normal blood pressure.
The combination of pindolol with thiazide-like diuretics has been shown to be compatible and generally more effective than either of the drugs used alone in reducing elevated blood pressure.
In humans, orally administered pindolol is rapidly and completely absorbed. Because of negligible hepatic first pass effect, the bioavailability of oral pindolol is high and approaches 90% of the oral dose. Maximum plasma concentrations are reached within 2 hours after oral administration and the plasma half-life is approximately 3.5 hours. The elimination of pindolol is not dose dependent.
In man, pindolol is partially metabolized with approximately 40% of an oral dose being excreted unchanged in the urine. The principal metabolites of pindolol consist of the conjugated glucuronide and phenolic derivatives of pindolol conjugated with sulfuric or glucuronic acid.
Approximately 80% of an oral dose is accounted for in the urine within 24 hours.
The onset of the diuretic action of hydrochlorothiazide occurs in 2 hours and the peak action in about 4 hours. Diuretic activity lasts about 6 to 12 hours. Hydrochlorothiazide is eliminated rapidly by the kidney.
Indications
This fixed combination is not indicated for initial therapy of hypertension. Hypertension requires therapy titrated to the individual patient. It is always better to adjust the dosage of each antihypertensive drug separately, but when the fixed combination corresponds to the optimum drug and dose requirements of the patient, its use may be more convenient in patient management. For further adjustment of dosage, however, it is best to use the individual drugs again. The treatment of hypertension is not static, but must be re-evaluated as conditions in each patient warrant.
Viskazide is indicated for the maintenance therapy of patients with hypertension who require pindolol and hydrochlorothiazide in the dosage and ratios present in Viskazide.
Precautions
Lactation
Thiazides appear in human milk. If use of Viskazide is deemed essential, the patient should stop nursing.
Children
The safety for use of pindolol in children has not been established; therefore, Viskazide is not recommended in the pediatric age group.
Pregnancy
Thiazides cross the placental barrier and appear in cord blood. The use of Viskazide in pregnancy or in women of child bearing potential requires that the anticipated benefit be weighed against possible risk to mother and/or fetus. These hazards include fetal or neonatal jaundice, thrombocytopenia, and possibly, other adverse reactions which have occurred in the adult.
Supplied
Viskazide 10/50
Each orange, round, compressed tablet, 9 mm diameter, one side slope-faced and bisected with “10/50” embossed on each side of the bisect, reverse side flat-faced with beveled edge and embossed with “VISKAZIDE” around the circumference and “
” centered, contains: pindolol 10 mg and hydrochlorothiazide 50 mg. Nonmedicinal ingredients: D&C Red #21 Aluminium Lake, D&C Yellow #10 Lake, magnesium stearate, microcrystalline cellulose, pregelatinized starch and silicon dioxide. Calendar packs of 35.
Viskazide 10/25
Each peach, round, compressed tablet, 9 mm diameter, one side slope-faced and bisected with “10/25” embossed on each side of the bisect, reverse side flat-faced with beveled edge and embossed with “VISKAZIDE” around the circumference and “” centered, contains: pindolol 10 mg and hydrochlorothiazide 25 mg. Nonmedicinal ingredients: D&C Red #21 Aluminium Lake, D&C Yellow #10 Lake, magnesium stearate, microcrystalline cellulose, pregelatinized starch and silicon dioxide. Calendar packs of 35.
Contraindications
The presence of: congestive heart failure (see Warnings); right ventricular failure secondary to pulmonary hypertension; significant cardiomegaly; sinus bradycardia, second and third degree AV block; cardiogenic shock; bronchospasm (including bronchial asthma), or severe chronic obstructive pulmonary disease (see Precautions); anesthesia with agents that produce myocardial depression, e.g., ether; anuria; hypersensitivity to pindolol, hydrochlorothiazide, or to sulfonamide derived drugs.
Warnings
Cardiac Failure: Special caution should be exercised when administering Viskazide to patients with a history of heart failure. Sympathetic stimulation is a vital component supporting circulatory function in congestive heart failure, and inhibition with beta-blockade always carries the potential hazard of further depressing myocardial contractility and precipitating cardiac failure.
In patients without a history of cardiac failure, continued depression of the myocardium over a period of time can, in some cases, lead to cardiac failure. Therefore, at the first sign or symptom of impending cardiac failure occurring during therapy, patients should be fully digitalized and/or given additional diuretic therapy, and the response observed closely.
Pindolol acts selectively without blocking the inotropic action of digitalis on heart muscle. However, the positive inotropic action of digitalis may be reduced by the negative inotropic effect of pindolol when the 2 drugs are used concomitantly. The effects of pindolol and digitalis are additive in depressing AV conduction. If cardiac failure persists, therapy with Viskazide should be discontinued (see below).
Abrupt Cessation of Therapy in Angina Pectoris: Patients with angina should be warned against abrupt discontinuation of Viskazide. There have been reports of severe exacerbation of angina, and of myocardial infarction or ventricular arrhythmias occurring in patients with angina pectoris, following abrupt discontinuation of beta-blocker therapy. The last 2 complications may occur with or without preceding exacerbation of angina pectoris. Therefore, when discontinuation of Viskazide is planned in patients with angina pectoris, the dosage should be reduced over a period of about 2 weeks and the patient should continue to be observed. The same frequency of administration should be maintained.
In situations of greater urgency, therapy should be discontinued step-wise and under conditions of closer observation. If angina markedly worsens or acute coronary insufficiency develops, it is recommended that treatment be reinstituted promptly, at least temporarily.
Since ischemic heart disease may be unrecognized, the above advice should be followed in patients considered to be at risk of having asymptomatic ischemic heart disease.
Various skin rashes and conjunctival xerosis have been reported with beta-blockers, including pindolol. A severe syndrome (oculo-mucocutaneous syndrome) whose signs include conjunctivitis sicca and psoriasiform rashes, otitis, and sclerosing serositis has occurred with the chronic use of one beta-adrenergic blocking agent (practolol). This syndrome has not been observed with pindolol, however, physicians should be alert to the possibility of such reactions and should discontinue treatment in the event that they occur.
Sinus bradycardia may occur with the use of pindolol due to unopposed vagal activity remaining after blockade of beta1-adrenergic receptors. Due to its intrinsic sympathomimetic activity (ISA), pindolol causes less bradycardia at rest than some other beta-adrenergic blocking agents. If excessive bradycardia occurs, the dosage should be reduced.
In patients with thyrotoxicosis, pindolol may give a false impression of improvement by diminishing peripheral manifestations of hyperthyroidism without improving thyroid function. Special considerations should be given to the potential of pindolol to aggravate congestive heart failure. Pindolol does not alter thyroid function tests. Patients suspected of developing thyrotoxicosis should be managed carefully to avoid abrupt withdrawal of beta-blockade which might precipitate a thyroid storm. Thiazides may decrease serum PBI levels without signs of thyroid disturbance.
In patients with renal disease, thiazides may precipitate azotemia, and cumulative effects may develop in the presence of impaired renal function. If progressive renal impairment becomes evident, Viskazide should be discontinued.
In patients with impaired hepatic function or progressive liver disease, even minor alterations in fluid and electrolyte balance may precipitate hepatic coma. Hepatic encephalopathy, manifested by tremors, confusion, and coma, has been reported in association with diuretic therapy including hydrochlorothiazide.
In patients receiving thiazides, sensitivity reactions may occur with or without a history of allergy or bronchial asthma.
The possible exacerbation or activation of systemic lupus erythematosus has been reported with thiazides.
Adverse Effects
Gastrointestinal
anorexia, gastric irritation, cramping, diarrhea, constipation, flatulence, heartburn, nausea and vomiting, abdominal pain, dry mouth, jaundice (intrahepatic, cholestatic), pancreatitis, sialoadenitis.
Hypersensitivity
exanthema, sweating, pruritus, purpura, photosensitivity, urticaria, exfoliative dermatitis, psoriasiform rash, necrotizing angiitis vasculitis, cutaneous vasculitis, fever, respiratory distress, including pneumonitis, anaphylactic reactions.
Hematologic
leukopenia, agranulocytosis, thrombocytopenia, aplastic anemia, hemolytic anemia.
Clinical Laboratory Test Findings
On rare occasions, changes in the following parameters were noted: elevations in transaminases, alkaline phosphate, LDH, serum uric acid; a reduction in bilirubin. The most common changes associated with the thiazide component are increases in uric acid and decreases in serum potassium and chloride.
Urogenital
impotence.
Special Senses
visual disturbances, including xanthopsia and transient blurred vision, dry eyes, conjunctivitis, itching and/or burning eyes, tinnitus, vestibular disorder.
Central Nervous System
insomnia, nightmares, vivid dreams, fatigue, drowsiness, weakness, paresthesias, dizziness, vertigo, tinnitus, headache, mental depression, nervousness. Rarely have the following adverse reactions been reported: aggressiveness, motor disorders, confusion, xanthopsia.
Other
hyperglycemia, glycosuria, hyperuricemia, muscle cramps, weakness, restlessness, weight gain or loss, urinary frequency, appetite stimulation.
Respiratory
shortness of breath and/or dyspnea, wheezing, bronchospasm (see Contraindications and Precautions).
Cardiovascular
congestive heart failure (see Warnings), severe bradycardia (see Warnings) may occur as may syncope, lightheadedness, and postural hypotension. Lengthening of PR interval, second degree AV block, palpitation, chest pains, cold extremities, Raynaud's phenomenon, claudication, hot flushes, very rarely arrhythmia, coronary insufficiency. Orthostatic hypotension may be potentiated by alcohol, barbiturates or narcotics.
Overdose
Symptoms
The pindolol component may cause bradycardia, hypotension, bronchospasm, hypoglycemia or acute cardiac failure.
The hydrochlorothiazide component may cause excessive diuresis with electrolyte depletion and dehydration. Signs are dry mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, gastrointestinal disturbances, mental confusion, delirium, convulsions, shock and 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
Discontinue Viskazide. There is no specific antidote. If ingestion is, or may have been, recent, gastric lavage or emesis may reduce absorption; when ingestion has been earlier, infusions may be helpful to promote urinary excretion.
If required the following therapeutic measures are suggested: Bradycardia: Atropine or another anticholinergic drug. Heart block: (second or third degree) Isoproterenol or transvenous cardiac pacemaker. Congestive heart failure: Conventional therapy. Hypotension: (depending on associated factors) Epinephrine rather than isoproterenol or norepinephrine may be useful in addition to atropine and digitalis. Bronchospasm: Aminophylline or isoproterenol. Hypoglycemia: I.V. glucose. Stupor or Coma: Supportive therapy as clinically warranted. Gastrointestinal Effects: Though usually of short duration, these may require symptomatic treatment.
Abnormalities in BUN and/or Serum Electrolytes: Monitor serum electrolyte levels and renal function; institute supportive measures as required individually to maintain hydration, electrolyte balance, respiration and cardiovascular-renal function.
It should be remembered that pindolol is a competitive antagonist of isoproterenol and hence large doses of isoproterenol can be expected to reverse many of the effects of excessive doses of Viskazide. However, the complications of excess isoproterenol should not be overlooked.
Dosage
Dosage must be determined for individual patients by titration of each component separately. Where the fixed combination in Viskazide supplies the dosage so determined, the combination product may be used for maintenance therapy. 1 or 2 Viskazide tablets once daily in the morning can be used to administer up to 20 mg pindolol and 100 mg hydrochlorothiazide.
If higher doses of either ingredient are needed, the individual components should be used.
When necessary, another antihypertensive agent may be added gradually, beginning with 50% of the usual recommended starting dose to avoid excessive reduction in blood pressure.
If dosage adjustment is necessary during maintenance therapy, it is advisable to use the individual drugs.
