Terbutaline Aminophylline

Bleomycin Bleomycin is incompatible and loses its potency if it is administered with solutions of benzylpenicillin sodium, carbenicillin, cephazolin or cephalothin sodium, hydrocortisone sodium succinate, mitomycin, methotrexate, nafcillin sodium, aminophylline, ascorbic acid, terbutaline, divalent and trivalent cations (especially copper), compounds containing sulfhydryl groups, and precipitation by hydrophobic anions, essential amino acids, riboflavine, dexamethasone, and frusemide. 

The use of subcutaneous sympathomimetic bronchodilator is indicated for the severe asthma attack that requires emergency treatment. Epinephrine and terbutaline are available for subcutaneous therapy and, in usual doses, are comparable in efficacy. By this route, terbutaline appears to be no more 3z selective than epinephrine and is reported to have more adverse effects (22). Aqueous suspension of epinephrine provides a longer duration of action. In status asthmaticus sympathomimetics are often not helpful. Intravenous aminophylline is the basic therapy in this setting. The acute therapy should be instituted with a loading dose, but this should be proportionally reduced if the patient has been on regular theophylline therapy. 

An infusion of isoprenaline increased the clearance of theophylline (given as intravenous aminophylline) by a mean of 19% in 6 children with status asthmaticus and respiratory failure. Two of them had increases in clearance of greater than 30%. Another study in 12 patients with status asthmaticus found that an isoprenaline infusion (mean maximum rate 0.77 micrograms/kg per minute) caused a mean fall in serum theophylline levels of almost 6 micrograms/mL. The levels rose again when isoprenaline was stopped. A critically ill patient receiving intravenous aminophylline, phenytoin and nebulised terbutaline had a marked 4.5-fold increase in theophylline clearance when an isoprenaline infusion and intravenous methylprednisolone were added to the regimen. ... 

Oral terbutaline decreased serum theophylline levels by about 10% in 6 asthmatics, but the control of asthma was improved. Another study in asthmatic children, found that terbutaline elixir 75 micrograms/kg three times daily reduced steady-state serum levels of theophylline by 22%, but the symptoms of cough and wheeze improved. Yet another study found no changes in the pharmacokinetics of aminophylline in asthmatic children given terbutaline. ... 

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