Management of Asthma and Chronic Airflow Limitation (Part 15)

A recent study illustrates the potential for serious toxicity from therapeutic misadventure with this drug. In a prospective four-month surveillance of potentially toxic theophylline levels in hospitalized patients at a major university hospital, 44 episodes in 39 patients were studied. In all of the patients, serum theophylline levels were over 20 |xg/ml (mean, 28 mg/ ml; range, 20-79 mg/ml); 30 percent of the episodes occurred on admission through the emergency department. The majority of these patients had toxic symptoms, yet in only 18 percent of patients were serum theophylline levels requested and in only 38 percent of these patients were these drugs withheld while awaiting the serum theophylline levels. Three deaths, all of them in elderly patients, were thought to be due to theophylline toxicity. The side effect profile of theophylline is contrasted to that of aerosol bronchodilators and aerosol corticosteroids in Table 3, which emphasizes the importance of carefully weighing the risk vs benefit of theophylline before commencing its use in patients. buy ampicillin
A recent study has raised the possibility that theophylline may induce behavioral abnormalities and reduce school performance in children.
Theophylline toxicity in children may cause visual hallucinations as a complication of high serum levels. Dysphoria or depression has also been associated with theophylline use in children. The mechanism of theophylline-induced central nervous system disturbances is poorly understood; however, it was recently demonstrated that aminophylline in doses commonly used in patients with COPD is associated with reduced cerebral blood flow and oxygenation and this may, at least in part, account for some of the abnormalities observed.

Table 3—Comparative Side Effect Profile of Drugs used in Treatment of Airflow Limitation

Methylxanthines

Beta Agonists

Anticholinergics

Corticosteroids

Nausea

Inhaled

Inhaled

Inhaled

Vomiting

Slight tremor

Dry mouth

Dysphonia

Dyspepsia

Slight anxiety

Bad taste

Slight adrenal suppression (>1.5 mg

Epigastric pain

Tachycardia

Blurred vision (rare)

beclomethasone)

Diarrhea

Slight hypokalemia (large doses)

Cough (oleic acid in MDI formulation)

Intestinal bleeding

Gastroesophageal reflux

Aspiration

Ingested/injected

Ingested/injected

Tachycardia

Tremor

Weight gain

Life-threatening arrhythmias

Moderate

Mood change

Cardiac arrest

Hypokalemia

Hypertension

Insomnia

Hyperglycemia

Ulcers

Headaches

Gastrointestinal bleeding

Irritability

Osteoporosis

Hyperexcitability

Cataract

Personality disorders (children)

Diabetes

Seizures

Reduced growth in children

Death

Adrenal suppression Avascular necrosis of the hip

Category: Asthma and Chronic Airflow Limitation

Tags: aminophylline, asthma, chronic airflow limitation, methylxanthine, theophylline