- Diseases of the cardiovascular system, in which an increase in heart rate may be undesirable: atrial fibrillation, tachycardia, chronic heart failure (CHF), ischemic heart disease (CHD), mitral stenosis, hypertension, acute bleeding;
- thyrotoxicosis (tachycardia may be worse);
- increased body temperature (may still increase due to suppression of activity of sweat glands);
- reflux-esophagitis, hernia of the esophageal opening of the diaphragm, combined with reflux esophagitis (decreased esophageal and gastric motility and relaxation of the lower esophageal sphincter may contribute to slowing the emptying of the stomach and enhancing gastroesophageal reflux through the sphincter with impaired function);
- diseases of the gastrointestinal tract (GIT), accompanied by obstruction: achalasia and stenosis of the pylorus (there may be a decrease in motor and tone, leading to obstruction and retention of stomach contents);
- atony of the intestine in elderly patients or weakened patients (possibly development of obstruction), paralytic ileus (possible development of obstruction);
- diseases with increased intraocular pressure: open-angle glaucoma (mydriatic effect may cause some increase in intraocular pressure, correction of therapy may be required), age over 40 (risk of undiagnosed glaucoma);
- ulcerative colitis (high doses can inhibit intestinal peristalsis, increasing the likelihood of paralytic intestinal obstruction, and possibly the manifestation or exacerbation of such a serious complication as a toxic megacolon);
- dry mouth (prolonged use may cause further intensification of xerostomia);
- Kidney failure (risk of side effects due to reduced excretion);
- chronic lung diseases, especially in children and weakened patients (a decrease in bronchial secretion can lead to thickening secret and formation of congestion in the bronchi);
- myasthenia gravis (the condition may worsen due to inhibition of the action of acetylcholine);
- autonomic neuropathy (urinary retention and paralysis of accommodation may be aggravated), prostatic hyperplasia without urinary tract obstruction, urinary retention or predisposition to it, or diseases accompanied by obstruction of the urinary tract (including the bladder neck due to prostatic hypertrophy) ;
- gestosis (hypertension is possible);
- brain diseases in children, (effects from the central nervous system may be intensified);
- Down's disease (possibly unusual pupil dilated and increased frequency cardiac contractions);
- central paralysis in children (reaction to anticholinergic drugs can be most pronounced);
- liver failure.