6 ADVERSE REACTIONS The pattern of adverse effects seen with dicylomine 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)]. The most serious adverse reactions include cardiovascular and central nervous system symptoms. The most common adverse reactions (> 5% of patients) are dizziness, dry mouth, vision blurred, nausea, somnolence, asthenia and nervousness (6) To report SUSPECTED ADVERSE REACTIONS, contact Watson Laboratories, Inc. at 1-800-272-5525 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data described below reflect exposure in controlled clinical trials involving over 100 patients treated for functional bowel/irritable bowel syndrome with dicyclomine hydrochloride at initial doses of 160 mg daily (40 mg four times a day) In these trials most of the side effects were typically anticholinergic in nature and were reported by 61% of the patients. Table 1 presents adverse reactions (MedDRA 13.0 preferred terms) by decreasing order of frequency in a side-by-side comparison with placebo. Table 1: Adverse reactions experienced in controlled clinical trials with decreasing order of frequency MedDRA Preferred Term Dicyclomine Hydrochloride (40 mg four times a day) % Placebo % Dry Mouth 33 5 Dizziness 40 5 Vision blurred 27 2 Nausea 14 6 Somnolence 9 1 Asthenia 7 1 Nervousness 6 2 Nine percent (9%) of patients were discontinued from dicyclomine hydrochloride because of one or more of these side effects (compared with 2% in the placebo group). In 41% of the patients with side effects, side effects disappeared or were tolerated at the 160 mg daily dose without reduction. A dose reduction from 160 mg daily to an average daily dose of 90 mg was required in 46% of the patients with side effects who then continued to experience a favorable clinical response; their side effects either disappeared or were tolerated. 6.2 Postmarketing Experience The following adverse reactions, presented by system organ class in alphabetical order, have been identified during post approval use of dicyclomine hydrochloride. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Cardiac disorders: palpitations, tachyarrhythmias Eye disorders: cycloplegia, mydriasis, vision blurred Gastrointestinal disorders: abdominal distension, abdominal pain, constipation, dry mouth, dyspepsia, nausea, vomiting General disorders and administration site conditions: fatigue, malaise Immune System Disorders: drug hypersensitivity including face oedema, angioedema, anaphylactic shock Nervous system disorders: dizziness, headache, hallucinations insomnia, somnolence, syncope Psychiatric disorders: As with the other anti-cholinergic drugs, cases of delirium or symptoms of delirium such as amnesia (or transient global amnesia), agitation, confusional state, delusion, disorientation, hallucination (including visual hallucination) as well as mania, mood altered and pseudodementia, have been reported with the use of Dicyclomine. Nervousness and insomnia have also been reported. Reproductive system and breast disorders: suppressed lactation Respiratory, thoracic and mediastinal disorders: dyspnoea, nasal congestion Skin and subcutaneous tissue disorder: dermatitis allergic, erythema, rash 6.3 Adverse Reactions Reported with Similar Drugs with Anticholinergic/Antispasmodic Action Gastrointestinal: anorexia, Central Nervous System: tingling, numbness, dyskinesia, speech disturbance, insomnia Peripheral Nervous System: With overdosage, a curare-like action may occur (i.e., neuromuscular blockade leading to muscular weakness and possible paralysis). Ophthalmologic: diplopia, increased ocular tension Dermatologic/Allergic: urticaria, itching, and other dermal manifestations; Genitourinary: urinary hesitancy, urinary retention in patients with prostatic hypertrophy Cardiovascular: hypertension Respiratory: apnea Other: decreased sweating,sneezing, throat congestion, impotence. With the injectable form, there may be temporary sensation of light-headedness. Some local irritation and focal coagulation necrosis may occur following the intramuscular injection of dicyclomine hydrochloride.