TYMLOS
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TYMLOS (TYMLOS).
Selective parathyroid hormone receptor agonist; stimulates osteoblast activity to increase bone formation and remodeling, leading to improved bone microarchitecture and density.
| Metabolism | Not extensively metabolized; eliminated via proteolytic degradation in the liver and other tissues. |
| Excretion | Renal (approximately 99% of absorbed dose excreted as inactive metabolites in urine), biliary/fecal (minimal, <1%) |
| Half-life | Terminal elimination half-life is approximately 30 minutes for the intact peptide; provides rapid clearance after subcutaneous administration, minimizing systemic accumulation. |
| Protein binding | Approximately 70-80% bound to plasma proteins, primarily to albumin. |
| Volume of Distribution | Approximately 1.2 L/kg, indicating distribution beyond extracellular fluid into tissues. |
| Bioavailability | Subcutaneous: Approximately 40% bioavailability relative to intravenous administration. |
| Onset of Action | Subcutaneous: Onset of bone turnover marker changes (e.g., P1NP increase) detectable within 2-4 weeks; clinical fracture risk reduction seen after 12-18 months. |
| Duration of Action | Subcutaneous: Effects on bone formation markers (P1NP) peak at 3-6 months, decline thereafter; treatment duration is limited to 18 months due to theoretical risk of osteosarcoma in clinical trials. |
| Molecular Weight | 411.5 |
80 mcg subcutaneously once daily.
| Dosage form | SOLUTION |
| Renal impairment | No dose adjustment required for GFR ≥30 mL/min; insufficient data for GFR <30 mL/min. |
| Liver impairment | No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B); not studied in severe impairment (Child-Pugh C). |
| Pediatric use | Not approved for pediatric use; safety and efficacy not established. |
| Geriatric use | No dose adjustment required based on age; consider renal function. |
| 1st trimester | No data in humans; animal studies show teratogenic effects at clinically relevant doses. Avoid use during first trimester. |
| 2nd trimester | No data in humans; animal studies show teratogenic effects. Avoid use. |
| 3rd trimester | No data in humans; risk of fetal harm. Avoid use. |
Clinical note
Comprehensive clinical and safety monograph for TYMLOS (TYMLOS).
| Placental transfer | Likely crosses placenta; molecular weight <1000 Da suggests transfer. |
| Breastfeeding | Excretion in human milk unknown; due to potential for serious adverse reactions, either discontinue drug or formula feed. |
| Lactation Rating |
■ FDA Black Box Warning
TYMLOS caused a dose-dependent increase in the incidence of osteosarcoma in male and female rats. The clinical relevance of this finding is unknown. Prescribe only for patients for whom the potential benefits are considered to outweigh the potential risk. Avoid use in patients at increased baseline risk for osteosarcoma (e.g., Paget's disease of bone, uncharacterized skeletal abnormalities, prior external beam or implant radiation therapy, or with open epiphyses).
| Serious Effects |
Pre-existing hypercalcemiaHistory of osteosarcoma or other bone malignancyPregnancy and women of childbearing potential not using effective contraceptionHypersensitivity to abaloparatide or any excipient
| Precautions | Risk of osteosarcoma (see boxed warning), Serum calcium: May cause hypercalcemia; monitor calcium levels and avoid in patients with pre-existing hypercalcemia, Risk of hypotension, including orthostatic hypotension; monitor blood pressure, Potential for urolithiasis in susceptible individuals, Bone safety: The safety and efficacy of treatment for more than 2 years have not been established; cumulative use beyond 2 years is not recommended |
| Food/Dietary |
Loading safety data…
| L4 - Possibly Hazardous |
| Teratogenic Risk | Teratogenic Risk Profile: TYMLOS (abaloparatide) is classified as Pregnancy Category C. Animal studies in rats and rabbits have shown fetal toxicity including skeletal abnormalities and decreased fetal weight at doses 3-20 times the human exposure. There are no adequate and well-controlled studies in pregnant women. The drug should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. First trimester: unknown risk; second and third trimesters: potential for fetal musculoskeletal abnormalities. |
| Fetal Monitoring | Maternal-Fetal Monitoring: Monitor serum calcium levels periodically during treatment as TYMLOS may cause hypercalcemia. Assess renal function. No specific fetal monitoring is recommended unless clinical signs warrant; however, routine prenatal care should be maintained. |
| Fertility Effects | Fertility Effects: In animal studies, abaloparatide did not impair fertility in male or female rats at doses up to 100 times the human exposure. There are no human data on fertility effects. |
| No specific food interactions. Maintain adequate calcium (1000-1200 mg/day) and vitamin D (≥800 IU/day) intake during therapy. |
| Clinical Pearls | TYMLOS (abaloparatide) is a PTHrP analog for osteoporosis; limit lifetime use to 2 years due to potential osteosarcoma risk seen in rat studies. Avoid in patients with Paget's disease, bone metastases, or unexplained alkaline phosphatase elevation. Administer subcutaneously in the abdomen or thigh; rotate injection sites. Monitor serum calcium within the first 4 weeks of therapy, as hypercalcemia may occur. |
| Patient Advice | This medication reduces fracture risk by stimulating new bone formation. · Inject subcutaneously once daily at about the same time each day. · Store in refrigerator (36°F to 46°F) in the original carton; do not freeze or shake. · Rotate injection sites (abdomen, thigh) to avoid lipodystrophy. · May cause nausea, dizziness, or headache; if persistent, contact your doctor. · Inform your doctor if you have Paget's disease, bone cancer, or high blood calcium levels. · Avoid concurrent use of other osteoporosis medications without provider approval. |