Seek emergency medical attention. Use caution when driving, operating machinery, or performing other hazardous activities. Guaifenesin and theophylline may cause dizziness. If you experience dizziness, avoid these activities. Avoid alcohol or use it with moderation while taking guaifenesin and theophylline.
Alcohol can increase the effects of theophylline leading to side effects.
Do not start or stop smoking without first talking to your doctor. Smoking changes the way your body uses theophylline, and you may need a dose adjustment. A change in brand or formulation may necessitate a different dosage. Avoid eating excessive amounts of grilled or char-broiled foods. These foods may affect how much theophylline you need.