Assess BP, pulse, respiratory status (rate, lung sounds, use of accessory muscles) before and throughout therapy. Ensure that oxygen therapy is correctly instituted during acute asthma attacks.

• Monitor intake and output ratios for an increase in diuresis or fluid overload.
• Patients with a history of cardiovascular problems should be monitored for chest pain and ECG changes (PACs, supraventricular tachycardia, PVCs, ventricular tachycardia). Resuscitative equipment should be readily available.
• Monitor pulmonary function tests before and periodically during therapy to determine therapeutic efficacy in patients with chronic bronchitis or emphysema.

Lab Test Considerations:

Monitor ABGs, acid-base, and fluid and electrolyte balance in patients receiving parenteral therapy or whenever required by patient's condition.

Monitor drug levels routinely, especially in patients requiring high doses or during prolonged intensive therapy. Obtain serum sample at time of peak absorption. Evaluate peak levels 30 min after a 30 min IV loading dose, 12–24 hr after initiation of a continuous infusion and 1–2 hr after rapid-acting oral forms, and 4–12 hr after extended-release oral forms. Therapeutic plasma levels range from 10–15 mcg/mL for asthma and 6–14 mcg/mL for apnea of prematurity. Drug levels in excess of 20 mcg/mL are associated with toxicity. Caffeine ingestion may falsely elevate drug concentration levels.

• Observe patient for symptoms of drug toxicity (anorexia, nausea, vomiting, stomach cramps, diarrhea, confusion, headache, restlessness, flushing, increased urination, insomnia, tachycardia, arrhythmias, seizures). Notify health care professional immediately if these occur. Tachycardia, ventricular arrhythmias, or seizures may be the first sign of toxicity. Geri: Patients over 60 yr have ↑ risk of toxicity and sensitivity to toxic effects due to age-related pharmacodynamic and pharmacokinetic changes. Theophylline doses should not exceed 400 mg/d. .