Table 1:
Characteristics of the tizanidine and cyclobenzaprine cohorts
| Tizanidine (n=1626) | Cyclobenzaprine (n=5012) | p-value | |
|---|---|---|---|
| Age (years), median [IQR]a | 52 [42,62] | 55 [42,64] | <0.001 |
| Sex | |||
| Female, n (%) | 1063 (65.38%) | 3315 (66.14%) | 0.21 |
| Male | 519 (31.92%) | 1598 (31.88%) | |
| Unknown | 44 (2.71%) | 99 (1.98%) | |
| Race | |||
| White | 1361 (83.70%) | 4104 (81.88%) | 0.006 |
| Black | 168 (10.33%) | 656 (13.09%) | |
| Other (and unknown) | 97 (5.97%) | 252 (5.03%) | |
| Co-exposure Drug | |||
| Ciprofloxacin | 1595 (98.09%) | 4936 (98.48%) | 0.31 |
| Fluvoxamine | 31 (1.91%) | 76 (1.52%) | |
| Systolic blood pressure at baseline (mm Hg) | 125 (112–140) | 126 (115–139) | 0.23 |
| Lowest Blood Pressure during study period | |||
| Systolic blood pressure (mm Hg) | 115 [100,130] | 117 [103,130] | 0.003 |
| Diastolic blood pressure (mm Hg) | 68.5 [59,79] | 70 [60,80] | 0.001 |
| Charlson comorbidities, by ICD9 codes | |||
| Myocardial Infarction | 65 (4.00%) | 205 (4.09%) | 0.94 |
| Congestive Heart Failure | 146 (8.98%) | 418 (8.34%) | 0.41 |
| Peripheral Vascular Disease | 72 (4.43%) | 176 (3.51%) | 0.10 |
| Cerebrovascular Disease | 137 (8.43%) | 324 (6.46%) | 0.008 |
| Dementia | 4 (0.25%) | 17 (0.34%) | 0.80 |
| Pulmonary Disease | 210 (12.92%) | 667 (13.31%) | 0.71 |
| Connective Tissue Disease | 13 (0.80%) | 59 (1.18%) | 0.22 |
| Peptic Ulcer Disease | 29 (1.78%) | 43 (0.86%) | 0.003 |
| Liver Disease | 61 (3.75%) | 177 (3.53%) | 0.70 |
| Diabetes with or without complication | 310 (19.07%) | 976 (19.47%) | 0.37 |
| Paralysis/Hemiplegia | 55 (3.38%) | 79 (1.58%) | <0.001 |
| Renal Disease | 150 (9.23%) | 460 (9.18%) | 0.96 |
| Malignancy with or without metastasis | 119 (7.32%) | 395 (7.88%) | 0.48 |
| HIV/AIDS | 14 (0.86%) | 45 (0.90%) | 1.000 |
| Modified Charlson Score | 0 [0,2] | 0 [0,2] | 0.09 |
| Concurrent anti-hypertensive drug | |||
| Angiotensin converting enzyme inhibitors | 439 (27.0%) | 1,340 (26.74%) | 0.85 |
| Angiotensin receptor blockers | 190 (12.1%) | 680 (13.57%) | 0.05 |
| Calcium channel blockers | 347 (21.34%) | 1,071 (21.37%) | 1.0 |
| Beta blockers | 539 (33.15%) | 1,656 (33.04%) | 0.95 |
| Diuretics | 592 (36.41%) | 1,831 (36.53%) | 0.95 |
| Alpha-agonists | 148 (9.1%) | 325 (6.48%) | 0.001 |
| Others | 113 (7.0%) | 285 (5.69%) | 0.07 |
| Propensity score | 0.24 (0.22–0.27) | 0.24 (0.22–0.26) | <0.001 |
Data are presented as median [interquartile range] for continuous variables and number (%) for categorical variables.
a
Missing age for 216. Baseline systolic blood pressure available in 4,353 patients. HIV: Human immunodeficiency virus, AIDS: Acquired Immunodeficiency syndrome.