PHARMACOLOGY

CHOLEDYL EXPECTORANT ELIXIR (oxtryphilline - guaifenesin) contains 64% theophylline and has the properties attributed to theophylline.

INDICATIONS

CHOLEDYL EXPECTORANT ELIXIR is indicated for the symptomatic treatment of reversible bronchoconstriction associated with chronic obstructive pulmonary emphysema, bronchial asthma, chronic bronchitis and related bronchospastic disorders and where expectoration is required.

CONTRAINDICATIONS

CHOLEDYL EXPECTORANT ELIXIR is contraindicated in those patients who have shown hypersensitivity to it or to other theophylline derivatives; in coronary artery disease when in the physician's judgment myocardial stimulation might prove harmful, in individuals with underlying seizure disorders (unless receiving appropriate anticonvulsant medication). It should not be used in patients with peptic ulcer.

PRECAUTIONS

Patients starting therapy should be carefully observed to determine if this fixed dose combination is suitable for them. The use of single drug preparations to allow for more accurate dose adjustment for each component may be preferable in some patients. The dose of oxtriphylline required to achieve therapeutic blood concentrations varies considerably among patients.

CHOLEDYL EXPECTORANT ELIXIR should not be administered more often than every 4 hours or within 12 hours following oral, parenteral or rectal use of other xanthine containing preparations. Simultaneous use of additional xanthines by any route should be avoided in all patients, especially children.

Children are very sensitive to xanthines; the margin of safety above therapeutic doses is small.

Drug Interactions : Synergism with ephedrine has been documented and may occur with other sympathomimetic amines. Theophylline may cause increased excretion of lithium carbonate. Theophylline antagonizes the effect of propranolol. Theophylline potentiates the effects of
diuretics and the cardiac effect of digitalis glycosides. The concomitant use of morphine, stilbamidine, curare may antagonize the effect of theophylline since these drugs stimulate histamine release and thereby induce bronchoconstriction.

Cigarette smoking and phenobarbital shorten, while alcohol consumption increases the half-life of theophylline.
Xanthines have been shown to be nephrotoxic with prolonged use at high dosage. Coincident toxicity should therefore be borne in mind when other potentially nephrotoxic drugs are administered concurrently.
Acidifying agents, by increasing urinary excretion of weak bases like the xanthines, inhibit theophylline action.
Alkalinizing agents, by decreasing urinary excretion of weak bases like the xanthines, potentiate theophylline action.
Combined use of several xanthines may cause excessive CNS stimulation.

Toxic reactions as a result of significant elevations of serum theophylline levels have been observed in patients after initiation of treatment with erythromycin preparations. Particular attention should therefore be directed toward monitoring the serum theophylline levels in such patients.

The methylxanthines increase blood levels of prothrombin and fibrinogen, shorten the prothrombin time and thus antagonize the effects of coumarin anticoagulants.

Xanthines antagonize the uricosuric action of probenecid and of sulfinpyrazone and uricosuric activity of pyrazolon derivatives.

Combined use of xanthines with sympathomimetics may cause excessive CNS stimulation.

Cimetidine, erythromycin, influenza vaccine and propranolol may increase the effect of theophylline by decreasing theophylline clearance.

ADVERSE EFFECTS

Gastric distress, palpitation and CNS stimulation may occur occasionally.
Others: tachypnea, hyperglycemia and inappropriate ADH syndrome.

OVERDOSE

Symptoms: Collapse, hypotension and excessive CNS stimulation. However, as with all theophylline products, marked gastric irritation occurs following overdosage and vomiting usually relieves the toxic level which may have been taken.
N.B.: Guaifenesin is a phenol (carbolic acid) derivative.

Treatment: Evacuate the stomach by lavage or emesis, followed by catharsis. Maintain blood pressure. Oxygen therapy as indicated. Usual measures for control of excessive CNS stimulation. See also Choledyl monograph.

DOSAGE

Usual maintenance doses: Patients over 14 years: 10 mL 4 times daily; 10 to 14 years: 5 mL 4 times daily.
The following mg equivalents facilitate changing from one xanthine preparation to another:
theophylline anhydrous 100 mg=aminophylline 118 mg=oxtriphylline 156 mg=theophylline sodium glycinate 200 mg.

SUPPLIED

Each 5 mL of red, cherry-flavored liquid contains: oxtriphylline 100 mg and guaifenesin 50 mg. Nonmedicinal ingredients: alcohol, anethole, citric acid, FD&C Red No. 2, FD&C Yellow No. 6, flavoring agents, glycerin, sodium citrate, sodium cyclamate and sugar.
Alcohol: 20%. Energy: 74.1 kJ (17.7 kcal)/5 mL. Sodium: <1 mmol (10.4 mg)/5 mL. Gluten-, lactose-, paraben-, sulfite- and tartrazine-free. Bottles of 250 and 500 mL.