From the Guidelines
Patients on Androgel can switch to intramuscular (IM) testosterone injections, but should not start injections immediately without consulting a healthcare provider to determine the appropriate timing and dosing. When considering the switch, it's essential to understand the differences in pharmacokinetics between Androgel (testosterone gel) and IM testosterone injections. Androgel provides daily hormone delivery with relatively stable levels, whereas injections create peaks and troughs in testosterone levels 1. The American College of Physicians suggests considering intramuscular rather than transdermal formulations when initiating testosterone treatment to improve sexual function in men with age-related low testosterone, as costs are considerably lower for the intramuscular formulation and clinical effectiveness and harms are similar 1. Key considerations for the transition include:
- Applying the last dose of Androgel and then beginning IM injections the following day or as directed by the provider
- Starting with a dose of 50-200mg of testosterone cypionate or enanthate every 1-2 weeks, individualized based on the patient's previous testosterone levels, response to gel therapy, and clinical needs
- Monitoring testosterone levels after 2-4 weeks to ensure proper dosing and adjust as necessary to maintain symptom control and avoid side effects like mood swings, fatigue, or excessive estrogen conversion 1. Given the potential for significant changes in testosterone levels and the risk of side effects, careful management by a healthcare provider is crucial to ensure a safe and effective transition from Androgel to IM testosterone injections.
From the Research
Switching from Androgel to IM Testosterone Injections
- When considering switching from Androgel (testosterone gel) to intramuscular (IM) testosterone injections, it's essential to understand the differences in administration and potential effects on testosterone levels.
- Studies have shown that subcutaneous (SC) injections can be an effective alternative to IM injections, with stable serum testosterone levels between injections 2.
- However, the question of whether a patient can start IM injections right away after being on Androgel is not directly addressed in the provided studies.
- It is known that testosterone therapy can be administered through various routes, including IM injections, SC injections, and transdermal gels like Androgel 3.
- When switching from one form of testosterone therapy to another, it's crucial to consider the pharmacokinetics and potential differences in serum testosterone levels 4, 5.
- A study on the pharmacokinetics and acceptability of SC injection of testosterone undecanoate found that the SC route is acceptable, but may produce greater pain 24 hours after injection compared to IM injection 5.
- Another study demonstrated that SC testosterone injections can achieve therapeutic and stable serum testosterone levels, similar to IM injections 2.
- While there is no direct evidence on switching from Androgel to IM injections, it's likely that a patient can start IM injections after being on Androgel, but the dosage and administration schedule may need to be adjusted to achieve optimal testosterone levels 3, 4.
Key Considerations
- The decision to switch from Androgel to IM testosterone injections should be made under the guidance of a healthcare professional.
- Patients should be monitored for potential changes in serum testosterone levels and adjusted accordingly.
- The choice of administration route depends on individual patient preferences, needs, and medical history 6, 4.