TERIPARATIDE
Clinical safety rating: safe
Animal studies have demonstrated safety
Teriparatide is a recombinant fragment of human parathyroid hormone (PTH 1-34). It acts by stimulating osteoblast activity, increasing bone formation, and improving bone microarchitecture.
| Metabolism | Teriparatide is metabolized via non-specific proteolytic degradation in the liver and peripheral tissues. No specific cytochrome P450 enzymes are involved. |
| Excretion | Primarily hepatic metabolism via nonspecific proteolytic enzymes; no significant renal or biliary excretion; minimal unchanged drug in urine or feces. |
| Half-life | Terminal half-life approximately 1 hour following subcutaneous administration; clinical duration limited by rapid clearance, necessitating once-daily dosing. |
| Protein binding | Approximately 40-50% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Approximately 0.2-0.3 L/kg, indicating distribution largely confined to extracellular fluid and bone. |
| Bioavailability | Subcutaneous: approximately 95% bioavailability. |
| Onset of Action | Subcutaneous: Onset of serum calcium elevation within 2-4 hours; peak bone formation marker response occurs within 24 hours. |
| Duration of Action | Duration of pharmacological effect (elevated serum calcium) lasts approximately 4-6 hours; once-daily dosing maintains intermittent PTH exposure. |
| Molecular Weight | 4117.8 |
20 mcg subcutaneously once daily.
| Dosage form | SOLUTION |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (CrCl >30 mL/min). Not recommended in severe renal impairment (CrCl ≤30 mL/min) due to lack of data. |
| Liver impairment | No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh class A or B). Not studied in severe hepatic impairment (Child-Pugh class C). |
| Pediatric use | Not approved for use in pediatric patients; safety and efficacy not established. |
| Geriatric use | No dose adjustment required; clinical studies included patients >65 years with no significant differences in efficacy or safety. |
| 1st trimester | Teriparatide is classified as FDA pregnancy category C. Animal studies have shown increased fetal skeletal abnormalities and reduced fetal weight at doses 2-8 times the human dose. There are no adequate and well-controlled studies in pregnant women. Use only if potential benefit justifies potential risk to the fetus. |
| 2nd trimester | Same as first trimester. Avoid use unless clearly needed. Teriparatide transiently increases serum calcium; maternal hypercalcemia may lead to neonatal hypocalcemia or suppress fetal parathyroid function. |
| 3rd trimester | Same as first and second trimesters. Consider risk of maternal hypercalcemia and potential effects on fetal calcium homeostasis. Discontinue if pregnancy occurs. |
Clinical note
No significant drug interactions Can cause orthostatic hypotension and increased risk of osteosarcoma.
| Placental transfer | Limited data. Based on molecular weight (~4118 Da) and peptide structure, some placental transfer is expected. Animal studies show transfer to fetal circulation. Human data absent. |
| Breastfeeding |
■ FDA Black Box Warning
Increased risk of osteosarcoma in animal studies. Avoid use in patients with Paget's disease of bone, unexplained elevations of alkaline phosphatase, open epiphyses, prior radiation therapy involving the skeleton, or bone metastases.
| Common Effects | Dizziness |
| Serious Effects |
Hypersensitivity to teriparatide or any componentPaget's disease of boneUnexplained elevation of alkaline phosphatasePrior radiation therapy involving the skeletonBone metastases or history of skeletal malignanciesMetabolic bone diseases other than osteoporosisPreexisting hypercalcemiaSevere renal impairment (CrCl <30 mL/min)
| Precautions | Risk of osteosarcoma (see black box warning), Orthostatic hypotension may occur, especially with initial doses, Hypercalcemia may occur; monitor serum calcium, Use with caution in patients with active urolithiasis, May increase serum uric acid |
| Food/Dietary |
Loading safety data…
| It is unknown whether teriparatide is excreted in human milk. However, due to its peptide nature (molecular weight ~4118 Da) and likely low oral bioavailability, excretion is low. Caution should be exercised when administered to a nursing woman. Observe infant for potential adverse effects. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | Insufficient human data; animal studies show skeletal abnormalities at high doses. No known risk in first trimester; avoid in second and third trimesters due to potential fetal skeletal effects. |
| Fetal Monitoring | Monitor serum calcium and phosphate levels in mother; consider fetal ultrasound for skeletal development if exposed in second/third trimester. |
| Fertility Effects | No adverse effects on fertility observed in animal studies; limited human data. |
| No specific food interactions. However, ensure adequate dietary calcium and vitamin D intake (e.g., dairy products, green leafy vegetables, fortified foods) to support the anabolic effect. Avoid excessive sodium, protein, and caffeine, which may increase calcium excretion. Do not take calcium supplements within 2 hours of teriparatide injection if instructed to take them separately, though generally they can be taken together. |
| Clinical Pearls | Teriparatide is a recombinant human parathyroid hormone analog used for osteoporosis. It is the only anabolic agent that stimulates new bone formation. Administer as a subcutaneous injection in the thigh or abdomen. Rotate injection sites. Do not use in patients with Paget's disease, unexplained alkaline phosphatase elevation, prior radiation therapy to the skeleton, or bone metastases. Maximum duration of therapy is 24 months over a patient's lifetime due to an increased risk of osteosarcoma in rats. Monitor serum calcium levels at baseline and periodically; may cause transient hypercalcemia 4-6 hours after dosing. Contraindicated in hypercalcemia, pregnancy, and lactation. |
| Patient Advice | Store teriparatide in the refrigerator at 2-8°C (36-46°F) and never freeze. Protect from light and do not use if the solution is cloudy, colored, or contains particles. · Inject once daily using the provided pen device. Administer at the same time each day, preferably in the morning, into the thigh or abdomen. Rotate injection sites to avoid lipodystrophy. · Sit or lie down during the first few doses if you experience dizziness or rapid heartbeat, as teriparatide may cause orthostatic hypotension. Stand up slowly. · Do not use teriparatide for more than 24 months total over your lifetime. Inform your doctor if you have Paget's disease, a history of radiation therapy, or bone cancer. · Contact your doctor if you have persistent nausea, vomiting, constipation, muscle weakness, or confusion, as these may be signs of hypercalcemia. · Take calcium and vitamin D supplements as recommended by your doctor, typically 1000 mg calcium and 800 IU vitamin D daily, to support bone formation. |