In two 12 week randomized, double-blind, placebo-controlled studies in 629 patients (placebo, N=253; 2.5 mg, N=121; 5 mg, N=255; 5-7.5 mg, N=114), the ability of pilocarpine hydrochloride tablets to stimulate saliva production was assessed. In these trials using varying doses of pilocarpine hydrochloride tablets (2.5-7.5 mg), the rate of saliva production was plotted against time. An Area Under the Curve (AUC) representing the total amount of saliva produced during the observation interval was calculated. Relative to placebo, an increase in the amount of saliva being produced was observed following the first dose of pilocarpine hydrochloride tablets and was maintained throughout the duration (12 weeks) of the trials in an approximate dose response fashion (See Clinical Studies section).
Two separate studies were conducted in patients with primary or secondary Sjogren's Syndrome. In both studies, the majority of patients best fit the European criteria for having primary Sjogren's Syndrome. ["Criteria for the Classification of Sjogren's Syndrome" (Vitali C, Bombardieri S, Moutsopoulos HM, et al: Preliminary criteria for the classification of Sjogren's syndrome. Arthritis Rheum 36:340-347, 1993.)]
A twelve week, randomized, double-blind, parallel-group, placebo-controlled study was conducted in 256 patients (14 men, 242 women) whose mean age was 57 years with a range of 24 to 85 years. The racial distribution was as follows: Caucasian 91%, Black 6%, and other 3%.
The effects of placebo were compared with those of pilocarpine hydrochloride tablets 5 mg four times a day (20 mg/day) for 6 weeks. At 6 weeks, the patients' dosage was increased from 5 mg pilocarpine hydrochloride tablets q.i.d. to 7.5 mg q.i.d. The data collected during the first 6 weeks of the trial were evaluated for safety and efficacy, and the data of the second 6 weeks of the trial were used to provide additional evidence of safety.
After 6 weeks of treatment, statistically significant global improvement of dry mouth was observed compared to placebo. "Global improvement" is defined as a score of 55 mm or more on a 100 mm visual analogue scale in response to the question, "Please rate your present condition of dry mouth (xerostomia) compared with your condition at the start of this study. Consider the changes to your dry mouth and other symptoms related to your dry mouth that have occurred since you have taken this medication." Patients' assessments of specific dry mouth symptoms such as severity of dry mouth, mouth discomfort, ability to speak without water, ability to sleep without drinking water, ability to swallow food without drinking, and a decreased use of saliva substitutes were found to be consistent with the significant global improvement described.
Another 12 week randomized, double-blind, parallel-group, placebo-controlled study was conducted in 373 patients (16 men, 357 women) whose mean age was 55 years with a range of 21 to 84. The racial distribution was Caucasian 80%, Oriental 14%, Black 2%, and 4% of other origin. The treatment groups were 2.5 mg pilocarpine tablets, 5 mg pilocarpine hydrochloride tablets, and placebo. All treatments were administered on a four times a day regimen.
After 12 weeks of treatment, statistically significant global improvement of dry mouth was observed at a dose of 5 mg compared with placebo. The 2.5 mg (10mg/day) group was not significantly different than placebo. However, a subgroup of patients with rheumatoid arthritis tended to improve in global assessments at both the 2.5 mg q.i.d. (9 patients) and 5 mg q.i.d. (16 patients) dose (10-20 mg/day). The clinical significance of this finding is unknown.
Patients' assessments of specific dry mouth symptoms such as severity of dry mouth, mouth discomfort, ability to sleep without drinking water, and decreased use of saliva substitutes were also found to be consistent with the significant global improvement described when measured after 6 weeks and 12 weeks of pilocarpine hydrochloride tablets use.
In the placebo-controlled clinical trials (see Clinical Studies section), the mean age of patients was approximately 55 years (range 21 to 85). The adverse events reported by those over 65 years and those 65 years and younger were comparable except for notable trends for urinary frequency, diarrhea, and dizziness (see ADVERSE REACTIONS section).
In controlled studies, 376 patients received pilocarpine, of whom 5% were men and 95% were women. Race distribution was 84% Caucasian, 9% Oriental, 3% Black, and 4% of other origin. Mean age was 55 years. The majority of patients were between 40 and 69 years (70%), 16% were 70 years and older and 14% were younger than 40 years of age. Of these patients, 161/629 (89/376 receiving pilocarpine) were over the age of 65 years. The adverse events reported by those over 65 years and those 65 years and younger were comparable except for notable trends for urinary frequency, diarrhea, and dizziness. The incidences of urinary frequency and diarrhea in the elderly were about double those in the non-elderly. The incidence of dizziness was about three times as high in the elderly as in the non-elderly. These adverse experiences were not considered to be serious. In the 2 placebo-controlled studies, the most common adverse events related to drug use were sweating, urinary frequency, chills, and vasodilatation (flushing). The most commonly reported reason for patient discontinuation of treatment was sweating. Expected pharmacologic effects of pilocarpine include the following adverse experiences associated with pilocarpine hydrochloride tablets:
| Adverse Event | Pilocarpine HCl | Placebo |
|---|
| 5 mg q.i.d. (20 mg/day) | (q.i.d.) |
|---|
| N=255 | N=253 |
|---|
| Sweating | 40% | 7% |
| Urinary Frequency | 10 | 4 |
| Nausea | 9 | 9 |
| Flushing | 9 | 2 |
| Rhinitis | 7 | 8 |
| Diarrhea | 6 | 7 |
| Chills | 4 | 2 |
| Increased Salivation | 3 | 0 |
| Asthenia | 2 | 2 |
In addition, the following adverse events (≥3% incidence) were reported at dosages of 20 mg/day in the controlled clinical trials:
| Adverse Event | Pilocarpine HCl | Placebo |
|---|
| 5 mg q.i.d. (20 mg/day) | (q.i.d.) |
|---|
| N=255 | N=253 |
|---|
| Headache | 13% | 19% |
| Flu Syndrome | 9 | 9 |
| Dyspepsia | 7 | 7 |
| Dizziness | 6 | 7 |
| Pain | 4 | 2 |
| Sinusitis | 4 | 5 |
| Abdominal Pain | 3 | 4 |
| Vomiting | 3 | 1 |
| Pharyngitis | 2 | 5 |
| Rash | 2 | 3 |
| Infection | 2 | 6 |
The following events were reported in Sjogren's patients at incidences of 1% to 2% at dosing of 20 mg/day: accidental injury, allergic reaction, back pain, blurred vision, constipation, increased cough, edema, epistaxis, face edema, fever, flatulence, glossitis, lab test abnormalities, including chemistry, hematology, and urinalysis, myalgia, palpitation, pruritus, somnolence, stomatitis, tachycardia, tinnitus, urinary incontinence, urinary tract infection, vaginitis.
The following events were reported rarely in treated Sjogren's patients (<1%) at dosing of 10-30 mg/day: Causal relation is unknown.
Body as a whole: chest pain, cyst, death, moniliasis, neck pain, neck rigidity, photosensitivity reaction
Cardiovascular: angina pectoris, arrhythmia, ECG abnormality, hypotension, hypertension, intracranial hemorrhage, migraine, myocardial infarction
Digestive: anorexia, bilirubinemia, cholelithiasis, colitis, dry mouth, eructation, gastritis, gastroenteritis, gastrointestinal disorder, gingivitis, hepatitis, abnormal liver function tests, melena, nausea & vomiting, pancreatitis, parotid gland enlargement, salivary gland enlargement, sputum increased, taste loss, tongue disorder, tooth disorder
Hematologic: hematuria, lymphadenopathy, abnormal platelets, thrombocythemia, thrombocytopenia, thrombosis, abnormal WBC
Metabolic and Nutritional: peripheral edema, Hypoglycemia
Musculoskeletal: arthralgia, arthritis, bone disorder, spontaneous bone fracture, pathological fracture, myasthenia, tendon disorder, tenosynovitis
Nervous: aphasia, confusion, depression, abnormal dreams, emotional lability, hyperkinesia, hypesthesia, insomnia, leg cramps, nervousness, parethesias, abnormal thinking, tremor
Respiratory: bronchitis, dyspnea, hiccup, laryngismus, laryngitis, pneumonia, viral infection, voice alteration
Skin: alopecia, contact dermatitis, dry skin, eczema, erythema nodosum, exfoliative dermatitis, herpes simplex, skin ulcer, vesiculobullous rash
Special senses: cataract, conjunctivitis, dry eyes, ear disorder, ear pain, eye disorder, eye hemorrhage, glaucoma, lacrimation disorder, retinal disorder, taste perversion, abnormal vision
Urogenital: breast pain, dysuria, mastitis, menorrhagia, metrorrhagia, ovarian disorder, pyuria, salpingitis, urethral pain, urinary urgency, vaginal hemorrhage, vaginal moniliasis
The following adverse experiences have been reported rarely with ocular pilocarpine: A-V block, agitation, ciliary congestion, confusion, delusion, depression, dermatitis, middle ear disturbance, eyelid twitching, malignant glaucoma, iris cysts, macular hole, shock, and visual hallucination.
The recommended dose of pilocarpine hydrochloride tablets is 5 mg taken four times a day. Efficacy was established by 6 weeks of use.