Dosing and uses of Trelstar, Trelstar Depot (triptorelin)
Adult dosage forms and strengths
powder for injection
- 3.75mg
- 11.25mg
- 22.5mg
Advanced Prostate Cancer
Due to different release characteristics, the dosage strengths are not additive and must be selected based upon the desired dosing schedule
22.5 mg IM q6Months, Or
11.25 mg IM q3Months, Or
3.75 mg IM qMonth
Administration
Reconstitution with diluent provided results in IM suspension
Administer as single IM injection in either buttock
Alter injection site periodically
Monitor
Serum testosterone, PSA
Pediatric dosage forms and strengths
<18 years: Safety and efficacy not established
Trelstar, Trelstar Depot (triptorelin) adverse (side) effects
>10%
Hot flushes (82%)
Skeletal pain (17%)
1-10%
Impotence (10%)
Headache (7%)
Hypertension (5%)
Injection site pain (5%)
Generalized pain (3%)
Vomiting (3%)
Fatigue (3%)
Insomnia (3%)
UTI (3%)
Diarrhea (2%)
Pruitus (2%)
UTI (2%)
Spinal cord compression (rare)
Postmarketing Reports
Pituitary apoplexy
Convulsions
Thromboembolic events including pulmonary emboli, CVA, MI, DVT, TIA, and thrombophlebitis
Warnings
Contraindications
Hypersensitivity
Use in women or children
Cautions
Risk of pituitary apoplexy (rare)
Hyperglycemia and an increased risk of developing diabetes have been reported in men receiving GnRH agonists
Cases of spinal cord compression, which may contribute to weakness or paralysis with or without fatal complications, have been reported with GnRH agonists
Reports of MI, sudden cardiac death, and stroke in men treated with GnRH agonists
QT prolongation
- Androgen deprivation therapy may prolong the QT/QTc interval; consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, frequent electrolyte abnormalities, and in patients taking drugs known to prolong the QT interval
- Electrolyte abnormalities should be corrected
- Consider periodic monitoring of ECG and electrolytes
Pregnancy and lactation
Pregnancy category: X
Lactation: not known if excreted in breast milk
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Trelstar, Trelstar Depot (triptorelin)
Mechanism of action
GnRH analog; decreases levels of LH and FSH resulting in suppression of steroidogenesis with subsequent decrease in testosterone (male) and estrogen (female) levels; a sustained decrease in LH and FSH secretion occurs after chronic and continuous administration
Pharmacokinetics
Half-Life: 3 hr
Protein Bound: None
Vd: 30-33 L
Time to peak: 1-3 hr
Metabolism: Unknown; may involve CYP metabolism
Metabolites: Not identified
Clearance: 150 mL/min
Excretion: urine (42%)
