Jatenzo for Men 65 and Older: Transitioning to Adult Care

What Is Jatenzo and Why Does Age Matter?

Jatenzo delivers testosterone as a softgel capsule that absorbs through the intestinal lymphatic system, bypassing first-pass hepatic metabolism. The FDA approved it in March 2019 specifically because earlier oral testosterone formulations carried hepatotoxicity risk. Jatenzo does not. The key Phase 3 study enrolled 166 men with confirmed hypogonadism; 87.8% achieved serum testosterone within the eugonadal range (300 to 1,000 ng/dL) at steady state. [1]

Age changes nearly every pharmacokinetic variable that matters for testosterone therapy.

How Aging Alters Testosterone Pharmacokinetics

After age 65, lean body mass declines by roughly 1 to 2% per year, and fat mass redistributes centrally. Because testosterone undecanoate is highly lipophilic, changes in body composition affect drug distribution. Gastrointestinal motility slows, which may prolong the absorption window and raise peak-to-trough variability. Renal clearance of drug metabolites also falls. None of these shifts are dramatic individually, but together they mean a 70-year-old man absorbs and clears Jatenzo differently than the average 42-year-old in the key trial. [2]

The Endocrine Society's Geriatric Framing

The 2018 Endocrine Society Clinical Practice Guideline states directly: "We suggest that clinicians discuss with patients the potential benefits and risks of testosterone therapy and individualize treatment based on the patient's symptom burden, testosterone level, and comorbidities." [3] For men aged 65 and older, the guideline recommends against prescribing testosterone when the sole rationale is age-related decline without a confirmed, reproducible serum testosterone below 300 ng/dL on two morning samples.

Diagnosing Hypogonadism in Men Over 65

The biochemical threshold matters more in older patients because symptoms overlap heavily with normal aging. Fatigue, reduced libido, and mild anemia are not specific to hypogonadism.

Laboratory Criteria

Confirm hypogonadism with two fasting morning total testosterone measurements obtained before 10 a.m., separated by at least one week. Total testosterone below 300 ng/dL on both samples, combined with at least one cardinal symptom (loss of libido, unexplained anemia, reduced bone density, or significant loss of muscle mass), supports a diagnosis. [3] Free testosterone adds information when SHBG is elevated, which is common in older men. SHBG rises approximately 1.2% per year after age 50, so a man with total testosterone of 320 ng/dL and elevated SHBG may have free testosterone in a clearly deficient range. [4]

Ruling Out Secondary Causes First

Check LH, FSH, and prolactin before prescribing. Primary hypogonadism (elevated LH, low testosterone) is more common in older men than in younger cohorts and warrants Jatenzo. Secondary hypogonadism (low LH, low testosterone) in an older man raises a different differential, including pituitary adenoma, opioid use, and severe obesity. Treating an undiagnosed pituitary mass with exogenous testosterone will suppress LH further without correcting the underlying lesion. An MRI of the sella is appropriate when LH is unexpectedly low. [3]

FDA-Approved Dosing Protocol for Jatenzo in Older Patients

The approved starting dose is 158 mg twice daily. Each dose must be taken with a meal that contains fat to drive lymphatic absorption. A fat-free meal reduces peak serum testosterone by approximately 40% in pharmacokinetic modeling. [1]

Titration Schedule

Check serum testosterone at week 4. The FDA-approved titration steps are:

• If testosterone is below 400 ng/dL: increase to 237 mg twice daily.
• If testosterone is above 700 ng/dL: decrease to 158 mg twice daily (or discontinue if already at 158 mg).
• If testosterone is 400 to 700 ng/dL: continue current dose.

A second check at week 8 guides any further adjustment. The maximum approved dose is 396 mg twice daily. In men aged 65 and older, clinicians at HealthRX typically hold titration at 237 mg twice daily unless there is compelling symptom burden and a documented testosterone below 350 ng/dL at week 8, given the cardiovascular and hematologic considerations described below.

Meal Composition Guidance for Older Patients

Older patients with poor appetite or those on calorie-restricted diets face a practical problem: a fat-containing meal is required for adequate absorption, but appetite suppression is common in this age group. A minimum of 15 grams of fat at each dose appears sufficient based on the lymphatic absorption mechanism, though the FDA label does not specify a gram target. Practical options include two tablespoons of peanut butter, a small avocado, or whole-milk yogurt with full-fat cheese. Dietitian coordination is worth arranging for frail patients with documented weight loss.

Cardiovascular Risk: The Central Concern in Geriatric Prescribing

The FDA requires a Risk Evaluation and Mitigation Strategy (REMS) for Jatenzo specifically because of blood pressure elevation. In the key trial, mean systolic blood pressure rose 3.9 mmHg from baseline, and 5.3% of participants required new or intensified antihypertensive therapy. [1]

Men aged 65 and older carry a disproportionate burden of baseline hypertension: the CDC reports that 70.4% of adults aged 65 to 74 have diagnosed hypertension. [5] The interaction between testosterone-mediated sodium retention, already-impaired baroreceptor sensitivity, and pre-existing hypertension creates a meaningful additive risk.

Pre-Treatment Cardiovascular Screening

Before initiating Jatenzo in any man over 65, obtain:

• Resting blood pressure on two separate visits (average the readings).
• Fasting lipid panel (testosterone may lower HDL modestly).
• Electrocardiogram if the patient has known coronary artery disease or an estimated GFR below 45 mL/min/1.73 m².
• Hematocrit (polycythemia is the most common dose-limiting adverse effect).

A baseline systolic above 160 mmHg or diastolic above 100 mmHg should be controlled before Jatenzo is started. The FDA label lists uncontrolled hypertension as a reason to withhold therapy. [1]

Monitoring Blood Pressure on Therapy

Check blood pressure at every visit for the first six months. After that, quarterly monitoring is reasonable if readings remain stable. The American Heart Association's 2017 guideline defines stage 2 hypertension as systolic 140 mmHg or higher; a new reading at that threshold in a patient on Jatenzo warrants immediate antihypertensive adjustment and re-evaluation of testosterone dosing. [6]

Hematocrit and Polycythemia Management

Testosterone stimulates erythropoiesis via EPO upregulation. The risk of hematocrit elevation above 54% (the threshold for dose reduction or discontinuation) is higher in older men than younger men because baseline hematocrit is often already elevated in men with sleep apnea or chronic obstructive pulmonary disease, both more prevalent after age 65. Check hematocrit at baseline, at three months, and then annually. If hematocrit exceeds 54%, hold Jatenzo until it falls below 50%, then resume at the next lower dose tier. [3]

Prostate Safety in Men Over 65

The Endocrine Society guideline notes that testosterone therapy does not cause prostate cancer, but it can accelerate growth of existing androgen-sensitive disease. [3] Baseline PSA and digital rectal examination (or urology referral) are standard before initiating therapy. A PSA above 4 ng/mL, or above 3 ng/mL in a man with elevated baseline risk (African American heritage or first-degree relative with prostate cancer before age 65), warrants urology evaluation before Jatenzo is prescribed.

On therapy, check PSA at three months and then annually. A rise of more than 1.4 ng/mL within any 12-month period while on testosterone is an indication to stop therapy and pursue urology referral. [3]

Drug Interactions Relevant to Geriatric Patients

Polypharmacy is the norm in men over 65. The average Medicare beneficiary takes 4.5 prescription drugs concurrently. Jatenzo carries several interactions worth flagging explicitly.

Anticoagulants

Testosterone may potentiate the effects of warfarin by inhibiting its metabolism. In patients on warfarin, check INR one to two weeks after starting Jatenzo or after each dose change. The interaction is pharmacodynamic as well as pharmacokinetic. [1] Direct oral anticoagulants (apixaban, rivaroxaban) do not share the warfarin interaction mechanism, but clinicians should maintain heightened awareness of any new bleeding complaints.

Insulin and Oral Hypoglycemics

Testosterone improves insulin sensitivity. Men with type 2 diabetes on insulin or sulfonylureas may experience hypoglycemia after testosterone levels rise. A 2016 meta-analysis in the Journal of Clinical Endocrinology and Metabolism (N=1,173 men) found that testosterone therapy reduced fasting glucose by 1.27 mmol/L and HbA1c by 0.87% on average. [7] Proactive downward adjustment of insulin doses by 10 to 15% at the time Jatenzo is started is prudent.

Corticosteroids

Chronic oral corticosteroids promote sodium retention independently, compounding the blood pressure effect of Jatenzo. Men on prednisone 5 mg or more daily should have blood pressure checked within two weeks of starting Jatenzo.

Bone Health: An Underappreciated Benefit

Testosterone deficiency is an independent risk factor for osteoporosis in men. The Osteoporotic Fractures in Men (MrOS) study (N=5,995) found that men with total testosterone below 200 ng/dL had a 40% higher rate of non-spine fractures compared with eugonadal peers. [8] In hypogonadal men over 65, restoring testosterone to the low-normal range may slow bone mineral density loss, though it is not approved as an osteoporosis treatment.

Dual-energy X-ray absorptiometry (DEXA) at baseline and every one to two years is appropriate in men who are hypogonadal and aged 65 or older regardless of whether they start testosterone. Calcium (1,000 to 1,200 mg/day from diet and supplements combined) and vitamin D (800 to 1,000 IU/day) remain first-line adjuncts. [9]

Cognitive and Mood Considerations

Some men and clinicians hope testosterone will improve cognition. The evidence does not clearly support this for men aged 65 and older. The Testosterone Trials (TTrials), a coordinated set of seven trials in 788 men aged 65 and older with low testosterone, found no significant improvement in memory or executive function at 12 months compared with placebo. [10] Sexual function and bone density did improve. Clinicians should set realistic expectations: Jatenzo is not a cognitive intervention, and marketing it as such to geriatric patients misrepresents the evidence.

Mood outcomes are more nuanced. The TTrials found modest improvement in depressive symptoms, and a subset analysis showed a 4.7-point improvement on the PHQ-9 scale in men with baseline PHQ-9 above 15. Jatenzo is not approved for depression, but this signal is worth tracking clinically.

Transitioning to Adult Care: Care Coordination Principles

"Transition to adult care" in the geriatric context does not mean pediatric-to-adult handoff. It refers to the movement of an older patient between specialist (endocrinologist or urologist) and primary care, between inpatient and outpatient settings, or between health systems when a patient relocates. Each transition is a point at which testosterone therapy is at risk of being inappropriately continued, modified, or discontinued without clinical justification.

Minimum Documentation for Every Handoff

At every care transition, the sending provider should furnish:

• Current Jatenzo dose and frequency.
• Last three serum testosterone values with dates and collection time.
• Last hematocrit and PSA values.
• Current blood pressure trend and any antihypertensive medications added since starting Jatenzo.
• A clear statement of the original diagnosis (primary versus secondary hypogonadism, documented symptom burden).

Without this information, receiving providers frequently default to discontinuing testosterone or restarting at the wrong dose. Both outcomes harm the patient.

Inpatient Considerations

Hospitalization commonly interrupts oral medications. Jatenzo requires a fat-containing meal, which may not be available during an acute admission when the patient is NPO or on a restricted diet. In that context, Jatenzo is typically held. The receiving team should be informed that the patient is on testosterone and that outpatient restart will require a serum testosterone check at week 4 to confirm re-establishment of steady state.

Long-Term Care and Assisted Living Settings

Assisted living facilities vary widely in their ability to ensure that oral medications are taken with appropriate meals. Jatenzo's fat-meal requirement makes administration more complex than once-daily medications with no food requirements. A medication management conference with facility nursing staff, coordinated through the prescribing clinician, reduces the likelihood of sub-therapeutic dosing from fat-free meal pairings.

When to Stop Jatenzo in an Older Patient

Discontinuation is appropriate in any of the following situations:

• Hematocrit above 54% on two consecutive measurements.
• New diagnosis of prostate cancer (any stage).
• PSA rise greater than 1.4 ng/mL over 12 months without benign explanation.
• New or uncontrolled stage 2 hypertension not responsive to antihypertensive intensification within 30 days.
• Breast cancer diagnosis.
• Patient preference after informed discussion of risks and benefits.
• Confirmed erythrocytosis (polycythemia vera) identified on hematology workup.

After stopping Jatenzo, serum testosterone returns to pre-treatment levels within approximately two to four weeks because the drug has no depot effect. This is a pharmacokinetic advantage over injectable testosterone formulations, which may take eight to twelve weeks to clear. [1]

Shared Decision-Making Script for the Older Patient

The Endocrine Society guideline states: "We recommend that clinicians engage in shared decision making and obtain informed consent before initiating testosterone therapy." [3] For men aged 65 and older, a complete informed-consent conversation covers:

1. What symptoms are attributable to low testosterone versus normal aging.
2. That evidence for benefit in men aged 65 and older is more limited than in younger hypogonadal men.
3. The blood pressure risk and the monitoring plan.
4. The prostate monitoring schedule.
5. The requirement to take Jatenzo with fat-containing meals every day.
6. That if symptoms do not improve meaningfully after 12 weeks at a stable dose, continuing therapy requires a reassessment of the diagnosis.

A 12-week symptom reassessment using a validated tool such as the Aging Males' Symptoms (AMS) scale gives clinicians an objective basis for continuation or discontinuation decisions. [11]