Doxiva

Indications

Doxiva is used to treat bronchial asthma, bronchospasm, chronic obstructive pulmonary disease (COPD), and pulmonary disease with a spastic bronchial component.

Pharmacology

Doxophylline is a novel bronchodilator. It structurally differs from Theophylline due to the presence of a dioxolane group in position 7. Doxophylline selectively inhibits phosphodiesterase 4, thereby relaxing bronchial smooth muscle. Unlike Theophylline, Doxophylline appears to have decreased affinity toward adenosine A1 and A2 receptors, which may account for its better safety profile. Doxophylline is reported to inhibit platelet activating factor (PAF) and the generation of leukotrienes.

Dosage & Administration

• Elderly: 200 mg tablet two or three times daily.
• Adults: 400 mg tablet two or three times daily or as prescribed by the physician.
• Children over 12 years of age: 10 ml syrup or 200 mg tablet two or three times daily.
• Children 6-12 years of age: 6-9 mg/kg body weight two times daily, or as prescribed by the physician. For example, if body weight is 10 kg, 3 ml (60 mg) two times daily.
• If the required daily dose of Doxophylline is 400 mg, Doxophylline SR tablet may be taken once daily or as prescribed by the physician.

Interaction

Doxiva should not be administered with other xanthine preparations. Consumption of beverages and food containing caffeine should be limited. Caution should be exercised when administering Doxiva with ephedrine or other sympathomimetic drugs. Erythromycin, TAO, lincomycin, clindamycin, allopurinol, cimetidine, influenza vaccine and propanolol may reduce the hepatic clearance of xanthine derivatives and increase plasma drug levels. Phenytoin, other anticonvulsants and cigarette smoking may increase clearance of xanthine derivatives and reduce their plasma half-life. In these cases, it may be necessary to increase the dosage of the drug.

Contraindications

Doxophylline is contraindicated in individuals with known hypersensitivity to the drug or other xanthine derivatives. It is also contraindicated in patients with acute myocardial infarction, hypotension and during lactation.

Side Effects

Patients treated with xanthine derivatives may experience nausea, vomiting, epigastric pain, headache, irritability, insomnia, tachycardia, extrasystoles and tachypnea. Rarely, hyperglycemia or albuminuria may occur. In case of overdose, severe cardiac arrhythmias and tonic-clonic seizure may occur. These effects may represent the first signs of intoxication. The appearance of side effects may require discontinuation of treatment and, at the physician's discretion, treatment may be resumed at lower doses after signs and symptoms of toxicity have subsided.

Pregnancy & Lactation

Animal tests have shown that Doxophylline does not interfere with pre and postnatal growth. However, there is insufficient clinical evidence about its effects during pregnancy, so use during pregnancy should be evaluated carefully on a case-by-case basis according to the risk-benefit ratio. The drug is contraindicated during lactation.

Precautions & Warnings

Factors that may reduce the hepatic clearance of xanthine derivatives and increase plasma drug levels include age, congestive cardiac decompensation, chronic obstructive pulmonary disease, severe liver disease, concomitant infections, and concurrent use of erythromycin, TAO, lincomycin, clindamycin, allopurinol, cimetidine, influenza vaccine and propanolol. In these cases, it may be necessary to reduce the dosage. When factors may influence clearance of xanthine derivatives, monitoring of blood drug concentration is recommended to control the therapeutic range.

Caution should be taken in patients with cardiac disease, hypertension, in the elderly, in patients with severe hypoxemia, hyperthyroidism, chronic cor pulmonale, congestive heart failure, liver disease, peptic ulcer and renal impairment. Particular caution is required in congestive heart failure because drug clearance is considerably slower and high blood levels may persist for long periods even after discontinuation. There is no risk of addiction or other form of dependence.

Overdose Effects

In case of overdose, severe cardiac arrhythmias and tonic-clonic seizure may occur and may represent the first signs of intoxication. Treatment may need to be discontinued and, at the physician's discretion, resumed at lower doses after toxicity has subsided. As there is no specific antidote, symptomatic treatment of cardiovascular collapse should be instituted in case of overdose.

Storage Conditions

Keep in a dry place away from light and heat. Keep out of the reach of children. Doxiva should be used only on prescription of a specialist physician.