Assessing compliance, acceptance, and tolerability of teriparatide in patients with osteoporosis who fractured while on antiresorptive treatment or were intolerant to previous antiresorptive treatment: an 18-month, multicenter, open-label, prospective study.

BACKGROUND: Teriparatide (parathyroid hormone [1-34] [ribosomal DNA origin]) stimulates new bone formation on trabecular and cortical (periosteal and/or endosteal) bone surfaces by preferential stimulation of osteoblastic activity over osteoclastic activity. It has been found to significantly reduce vertebral fractures by 65%, and nonvertebral fragility fractures by 53% in treatment-naive postmenopausal women who have previously suffered a vertebral fracture.
OBJECTIVE: This study examined the compliance, acceptance, and adherance of SC teriparatide 20 pg QD.
METHODS: In this 18-month, multicenter, openlabel, prospective study, women with postmenopausal osteoporosis, and men >30 years of age with either idiopathic or hypogonadal osteoporosis (with low bone mass [T-score of -1 or worse] and > or =1 fragility fracture), who had experienced a treatment-related adverse event (AE) or an inadequate response while receiving antiresorptive treatment, and who were willing to receive open-label teriparatide for > or =18 months were eligible. Compliance was defined as self-reported use of > or =80% of study medication. Acceptance of the injection pen was determined by scores obtained from questionnaires and rating scales measuring patients' perception. Patients self-reported on injection discomfort, ease of use, and the overall injection administration. Acceptance was assessed at baseline, and 3, 6, and 18 months. AEs were recorded at each clinical visit from the patients' self-reports. At the 3-month visit, a serum calcium level was drawn > or =16 hours after the previous teriparatide dose.
RESULTS: In this study, 116 patients-102 women with postmenopausal osteoporosis and 14 men (12 with idiopathic osteoporosis and 2 with hypogonadal osteoporosis)-were assessed for inclusion in the study. The mean (SD) age was 68.8 (11.1) years (range, 40-89 years) and the mean (SD) weight was 60.5 (11.7) kg (range, 37-87 kg). Seventy-three percent of the patients in this study had baseline spinal T-scores < or =-2.5, and 72% had fractured during treatment with an osteoporosis medication. Reported compliance was 89% at 6 months and 82% at 18 months. At baseline, 42% of patients were concerned about injection discomfort, and 43% were somewhat concerned with daily injections, while 7% were quite concerned. At 6 months, most patients reported much less concern (49%) or no concern (42%). Patient perceptions associated with learning how to use the pen injection, attaching the needle, holding the pen, and injecting the dose, improved during the first 6 months of the study. The most commonly reported AEs were dizziness, 12 (10.3%); nausea, 12 (10.3%); back pain, 9 (7.8%); and muscle cramps, 9 (7.8%). No AEs were believed to be associated with the use of the pen injection or teriparatide. Five patients had mildly elevated serum calcium concentrations (maximum value 2.8 mmol/L) at 3 months. However, all were normal on repeat testing approximately 4 weeks thereafter.
CONCLUSIONS: This study found that teriparatide pen injection was well accepted in these patients, and acceptance rates improved during the first 6 months of treatment and, thereafter, improved slightly for approximately 18 months. Reported compliance remained high throughout the study (82%-89%). Teriparatide pen injection was a viable treatment in these osteopenic or osteoporotic patients with fragility fractures.