A prospective evaluation of elevated serum theophylline concentrations to determine if high concentrations are predictable
Article Abstract:
The drug theophylline dilates the bronchi, or airways, and is used to treat asthma. The adverse side effects of theophylline are more severe with increasing dosages and include stimulation of the central nervous system, loss of appetite, abdominal discomfort, nausea, vomiting, abnormal heart rhythms, and seizures. Theophylline is most effective at blood levels greater than 10 milligrams per liter (mg/L), whereas adverse side effects develop at blood levels greater than 20 mg/L. Hence, for maximal treatment effects without adverse side effects, appropriate blood levels of theophylline range between 10 and 20 mg/L. Excessive blood levels of theophylline may result from errors made by patients, physicians, nurses, or pharmacists. The ability to predict blood levels of theophylline of 25 mg/L or higher was assessed using pharmacokinetic calculations. Pharmacokinetics refers to features describing the absorption, distribution, metabolism, and elimination of a drug. The study involved 55 patients with blood levels of theophylline of at least 25 mg/L. Of the 6,368 blood samples tested, theophylline levels were 25 mg/L or higher in 69 samples taken from the 55 patients. High theophylline levels could be predicted in 23 of 33 cases. Excessive blood levels of theophylline were due to a decrease in the drug's elimination in patients with congestive heart failure, chronic obstructive pulmonary disease, or liver disease. Excessive theophylline levels may have contributed to two of five deaths and caused fainting spells in three patients. The elimination of theophylline was overestimated in eight elderly patients with heart and lung disease. Nursing and pharmacy errors resulted in the simultaneous administration of two theophylline preparations to three patients. These findings suggest that elevated theophylline levels can be predicted and prevented using pharmacokinetic measurements. Most patients with elevated theophylline levels were older than 60 years and had co-existing diseases. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: American Journal of Medicine
Subject: Health care industry
ISSN: 0002-9343
Year: 1991
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Theophylline toxicity: clinical features of 116 consecutive cases
Article Abstract:
The drug theophylline is used to relieve bronchospasm (constriction of the bronchi or airways) and is often prescribed for patients with asthma. Various aspects of theophylline toxicity were assessed, including predisposing factors, clinical and laboratory characteristics, treatment, and prognosis. The therapeutic range of theophylline is 10 to 20 milligrams per liter (mg/L). Of 116 cases with blood theophylline levels greater than 30 mg/L, 14 were due to acute or sudden overdose and 102 were due to chronic overmedication. Factors which increased the risk of excessive theophylline levels were mistakes in dosing made by either patients or physicians, and conditions or drugs that decreased the elimination of theophylline from the body. Adverse effects were identified in 109 patients with high theophylline levels. Toxic effects were mild in 50 percent of the patients (nausea, nervousness, rapid heartbeat), moderate in 38 percent (tiredness, vomiting blood, abnormal heart rhythms), and severe or life-threatening in 7 percent of patients (abnormal heart rhythms, seizures, shock). Seven patients died from toxicity or with toxic theophylline levels. Compared with chronic overmedication, sudden overdose was more commonly associated with higher peak or maximum levels of theophylline, younger age, and greater risk of death. Three patients died from theophylline overdose and had levels greater than 100 mg/L; four patients with chronic overmedication had theophylline levels of 40 to 60 mg/L and died from respiratory failure. The charcoal hemoperfusion procedure was effective in identifying patients with acute overdose, but not those with chronic overmedication who are likely to suffer serious complications, including death. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: American Journal of Medicine
Subject: Health care industry
ISSN: 0002-9343
Year: 1990
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The effect of temafloxacin on the pharmacokinetics of theophylline
Article Abstract:
Temafloxacin is a new type of antibiotic belonging to the fluoroquinolone group. It kills a wide variety of gram-positive and gram-negative bacteria, including many organisms that cause respiratory tract infections. Theophylline is an agent that dilates the bronchi of the lungs and is commonly prescribed for patients with respiratory tract infections. An increased level of theophylline can result in toxicity. Other types of fluoroquinolones have been shown to adversely interact with theophylline. To determine the effect of temafloxacin on the metabolism of and the removal of theophylline from the body, 12 healthy subjects were assessed. The levels of theophylline in the blood did not change after oral temafloxacin was administered to the participants. Two of the 12 subjects (16 percent) showed a decrease in clearance, two (16 percent) showed an increase, and eight (67 percent) did not have a change in the time of clearance. These results demonstrate that in healthy subjects there was no significant interaction between theophylline and temafloxacin; the two drugs can be used together with little risk of theophylline toxicity. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: American Journal of Medicine
Subject: Health care industry
ISSN: 0002-9343
Year: 1991
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