aminophylline (Norphyl)

What is aminophylline, and how does it work (mechanism of action)?

Aminophylline is a methylxanthine bronchodilator composed of theophylline (Respbid, Slo-Bid, Theo-24, Theolair) and ethylenediamine. The mechanism of action of aminophylline is not completely understood. Theophylline relaxes smooth muscle in the respiratory tract and suppresses airway stimuli. Theophylline also increases contraction of diaphragm muscles by increasing calcium uptake through chemical channels.

What brand names are available for aminophylline?

Norphyl, Phyllocontin, Truphylline.

Is aminophylline available as a generic drug?


Do I need a prescription for aminophylline?


What are the side effects of aminophylline?

: Side effects of aminophylline are:

What is the dosage for aminophylline?

Dosing is based on patient's ideal body weight. In adults a loading dose of 5.7 mg/kg administered intravenously over 30 minutes followed by a continuous maintenance infusion of 0.5 mg/kg/hr for non-smokers 60 years or younger and 0.38 mg/kg/hour for those 60 years and older.


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Which drugs or supplements interact with aminophylline?

Aminophylline (or theophylline) should not be used with drugs like cimetidine (Tagamet), erythromycin, interferons, enoxacin, thiabendazole, and tacrine (Cognex) because they slow down theophylline metabolism, leading to significantly increased theophylline levels.

Aminophylline (or theophylline) should not be used with drugs like carbamezapine, phenobarbital, and rifampin because they accelerate theophylline metabolism, leading to significantly decreased theophylline levels.

Smoking increases the breakdown of theophylline reducing theophylline blood levels.

Is aminophylline safe to take if I'm pregnant or breastfeeding?

Theophylline is excreted into breast milk and may cause irritability or other signs of mild toxicity in nursing infants. Therefore, it should not be used in nursing mothers or use with extreme caution under medical supervision.

What else should I know about aminophylline?

What preparations of aminophylline are available?

Aminophylline is available in 25 mg/ml single-use, 10 ml (250 mg) and 20 ml (500 mg) vials and ampules.

How should I keep aminophylline stored?

Store Aminophylline between 20 C to 25 C (68 F to 77 F), protected from light.


Aminophylline injection (Norphyl, Phyllocontin, Truphylline) is a bronchodilator injection drug used for the management of acute worsening of asthma or COPD. Side effects, drug interactions, dosage, and pregnancy safety information should be reviewed prior to administering this medication.

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Aminophylline dihydrate Prescribing Information.