From the Guidelines
Long-term use of dicyclomine is associated with significant anticholinergic side effects, including cognitive impairment, constipation, urinary retention, and increased risk of dementia in elderly patients, as evidenced by the anticholinergic burden and its effects on aging physiology 1.
Side Effects of Dicyclomine
The side effects of long-term dicyclomine use can be categorized into common anticholinergic effects and less common but more serious effects. Common side effects include:
- Dry mouth
- Blurred vision
- Constipation
- Urinary retention
- Increased heart rate
- Drowsiness
- Dizziness
- Headaches
- Weakness
These effects are a result of dicyclomine's broad muscarinic receptor blockade, which affects not only the intestinal smooth muscle but also other organ systems where acetylcholine plays important roles 1.
Serious Side Effects and Considerations
Rare but serious side effects of long-term dicyclomine use include:
- Closed-angle glaucoma
- Heat stroke due to decreased sweating
- Allergic reactions Additionally, long-term use has been associated with an increased risk of dementia in elderly patients due to its anticholinergic properties, highlighting the need for cautious use and monitoring in this population 1.
Management and Recommendations
Given the potential for significant side effects, it is recommended to use dicyclomine with caution, particularly in older adults, and to regularly assess the need for continued use. Patients should be monitored for signs of anticholinergic burden, and alternative treatments should be considered when possible. Abrupt discontinuation after long-term use can lead to withdrawal symptoms, so tapering is recommended 1.
From the FDA Drug Label
The pattern of adverse effects seen with dicyclomine is mostly related to its pharmacological actions at muscarinic receptors [see Clinical Pharmacology (12)] . They are a consequence of the inhibitory effect on muscarinic receptors within the autonomic nervous system. These effects are dose-related and are usually reversible when treatment is discontinued The most serious adverse reactions reported with dicyclomine hydrochloride include cardiovascular and central nervous system symptoms [see Warnings and Precautions ( 5.2,5.3)]. Table 1 presents adverse reactions ( MedDRA 13. 0 preferred terms) by decreasing order of frequency in a side-by-side comparison with placebo The following adverse reactions, presented by system organ class in alphabetical order, have been identified during post approval use of dicyclomine hydrochloride.
The side effects of long-term use of dicyclomine include:
- Anticholinergic effects: dry mouth, dizziness, vision blurred, nausea, somnolence, asthenia, nervousness
- Cardiovascular symptoms: palpitations, tachyarrhythmias, hypertension
- Central nervous system symptoms: dizziness, headache, somnolence, syncope, delirium, agitation, confusional state, delusion, disorientation, hallucination
- Gastrointestinal symptoms: abdominal distension, abdominal pain, constipation, dry mouth, dyspepsia, nausea, vomiting
- Other symptoms: fatigue, malaise, suppressed lactation, dyspnoea, nasal congestion, dermatitis allergic, erythema, rash 2
From the Research
Side Effects of Long-Term Use of Dicyclomine
- The study 3 examined the efficacy and safety of antispasmodics, including dicyclomine, for the treatment of chronic abdominal pain in patients with common disorders of gut-brain interaction.
- However, the study 3 noted that comparisons of studies are limited by inconsistencies in treatment dosing and duration, patient profiles, and diagnostic criteria employed, making it difficult to determine the specific side effects of long-term use of dicyclomine.
- The study 3 also found that the antispasmodics evaluated, including dicyclomine, vary dramatically in efficacy and safety, and that each agent should be considered on an individual basis.
- Another study 4 focused on the efficacy of mebeverine in the treatment of irritable bowel syndrome, and did not provide information on the side effects of long-term use of dicyclomine.
- Overall, there is limited information available on the specific side effects of long-term use of dicyclomine, and further research is needed to fully understand its safety profile 3.