Injection-Site Pain in Patients With Multiple Sclerosis: Interferon Beta-1b Versus Interferon Beta-1a

A single-center, open-label, comparative pilot study was undertaken to assess injection-site pain associated with 10 consecutive subcutaneous injections of interferon beta-1b 250 μg every other day or interferon beta-1a 44 μg three times weekly in patients with multiple sclerosis (MS). Injection-site pain was assessed by the patients with a 10-cm visual analog scale (VAS) score. Recordings were made before each injection and at 10 minutes, 1 hour, and 24 hours postinjection. Ten patients were enrolled in each treatment group. The proportion of injections associated with no pain or no increase in pain at 1 hour postinjection was higher with interferon beta-1b (47%) than with interferon beta-1a (27%). Mean pain severity was also less intense with interferon beta-1b than with interferon beta-1a. Differences in VAS scores were seen immediately after injection (1.04 versus 3.14 cm, respectively) and at 10 minutes (0.40 versus 1.70 cm) and 1 hour (0.33 versus 1.50 cm) postinjection. These findings indicate that subcutaneous injection with interferon beta-1b is associated with a lower incidence and severity of pain than subcutaneous injection with interferon beta-1a in patients with MS. The results should assist MS nurses and physicians in supporting patients to make an informed choice regarding potential side effects when deciding on an appropriate disease-modifying therapy.