AMINOPHYLLINE 100MG TABLET

Indications

• Asthma
• Chronic obstructive pulmonary disease (COPD)
• Acute bronchospasm
• Apnoea of prematurity

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines based on age, weight, and clinical condition.

Adults: Refer to the BNF for appropriate dosing guidelines based on the specific clinical scenario, severity of the condition, and patient response.

Mechanism of action

Aminophylline works as a non-selective phosphodiesterase inhibitor, leading to increased levels of cyclic AMP (cAMP) within cells. This results in relaxation of bronchial smooth muscle, inhibition of inflammatory mediator release, and enhanced mucociliary clearance. Additionally, it has some anti-inflammatory effects and may improve respiratory muscle function.

Pharmacodynamics

The pharmacodynamic effects of aminophylline include bronchodilation, increased respiratory muscle endurance, and a reduction in airway resistance. Its action on cAMP levels contributes to the inhibition of bronchoconstriction and promotes vasodilation. Aminophylline's anti-inflammatory properties may also help in managing airway inflammation associated with asthma and COPD.

Pharmacokinetics

Aminophylline is administered intravenously or orally. It has a bioavailability of approximately 100% when given intravenously and about 50-70% when taken orally. The drug is metabolized in the liver by cytochrome P450 enzymes, primarily CYP1A2, and has a half-life of 3-8 hours, depending on various factors including age, smoking status, and concurrent medications. Excretion occurs mainly via the kidneys.

Contra-indications

• Hypersensitivity to aminophylline or any of its components
• Active peptic ulcer disease
• Severe coronary artery disease

Adverse effects

• Nausea
• Vomiting
• Anxiety
• Tachycardia
• Headache
• Insomnia
• Gastrointestinal disturbances
• Palpitations

Interactions

• beta blockers: Severe (increases risk of bronchospasm)
• aminophylline and phosphodiesterase type inhibitors: Severe (increases exposure)
• stiripentol and aminophylline: Severe (increases exposure)
• deferasirox and aminophylline: Severe (increases exposure)
• aminophylline and roflumilast: Severe (increases exposure)
• aciclovir and aminophylline: Moderate (increases exposure)
• aminophylline and macrolides: Moderate (decreases exposure)
• aminophylline and erythromycin: Moderate (decreases exposure)
• mexiletine and aminophylline: Moderate (increases exposure)
• monoclonal antibodies and aminophylline: Moderate (decreases exposure)

Precautions

• Use with caution in patients with cardiovascular disorders
• Monitor for signs of toxicity, particularly in patients with liver disease
• Use cautiously in patients with hyperthyroidism or diabetes mellitus

Pregnancy

Aminophylline should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Aminophylline is excreted in breast milk. Caution should be exercised when administering to breastfeeding women.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Aminophylline injection
• Aminophylline oral tablets
• Aminophylline oral solution