Introduction
Sunlenca (lenacapavir) and Sunosi (solriamfetol) are two distinct medications with different therapeutic applications. Sunlenca is a novel first-in-class capsid inhibitor developed for the treatment of HIV-1 infection, while Sunosi is a dopamine and norepinephrine reuptake inhibitor indicated for excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea. This monograph provides comprehensive clinical information about both medications.
Mechanism of Action
Sunlenca (lenacapavir): Binds to the HIV-1 capsid protein at a unique site, interfering with multiple essential steps of the viral lifecycle, including capsid-mediated nuclear import of viral DNA, virus assembly and release, and capsid core formation. Sunosi (solriamfetol): Functions as a dopamine and norepinephrine reuptake inhibitor (DNRI), increasing extracellular concentrations of these neurotransmitters in the brain, which promotes wakefulness without acting as a direct stimulant.Indications
Sunlenca: In combination with other antiretroviral agents for treatment of HIV-1 infection in heavily treatment-experienced adults with multidrug resistant HIV-1 infection failing their current antiretroviral regimen due to resistance, intolerance, or safety considerations. Sunosi: To improve wakefulness in adults with excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea.Dosage and Administration
Sunlenca:- Loading dose: 927 mg subcutaneously and 600 mg orally (as two 300 mg tablets) on Day 1
- Maintenance: 927 mg subcutaneously every 6 months or 600 mg orally every 6 months
- Renal impairment: No dosage adjustment required
- Hepatic impairment: No dosage adjustment required
- Initial dose: 75 mg once daily upon awakening
- May increase to 150 mg daily after at least 3 days
- Maximum dose: 150 mg daily for narcolepsy, 150 mg daily for OSA
- Renal impairment: Adjust based on creatinine clearance
- Hepatic impairment: Use with caution
Pharmacokinetics
Sunlenca:- Absorption: Oral bioavailability ~10-20%
- Distribution: Extensive tissue distribution with long half-life
- Metabolism: Primarily via CYP3A4 and UGT1A1
- Elimination: Half-life ~10-12 weeks
- Excretion: Primarily fecal
- Absorption: Rapid with peak concentrations at ~2 hours
- Distribution: 20% protein bound
- Metabolism: Minimal hepatic metabolism
- Elimination: Half-life ~7 hours
- Excretion: Primarily renal (95% unchanged)
Contraindications
Sunlenca: Hypersensitivity to lenacapavir or any component of the formulation Sunosi:- Hypersensitivity to solriamfetol
- Patients with end-stage renal disease
Warnings and Precautions
Sunlenca:- Immune reconstitution syndrome
- Potential risk of resistance if used without other active antiretrovirals
- Long-acting properties require careful consideration before initiation
- Cardiovascular effects: Increases blood pressure and heart rate
- Psychiatric symptoms: May cause anxiety, insomnia, or irritability
- Potential for abuse and dependence
- Use caution in patients with cardiovascular disease
- Monitor for emergence of psychiatric symptoms
Drug Interactions
Sunlenca:- Strong CYP3A inducers: Avoid concomitant use (rifampin, carbamazepine, St. John's wort)
- Moderate CYP3A inducers: Use with caution
- Drugs affecting gastric pH: May alter absorption
- MAO inhibitors: Contraindicated (risk of hypertensive crisis)
- Other sympathomimetic agents: Additive cardiovascular effects
- Drugs that increase blood pressure: Enhanced pressor effects
Adverse Effects
Sunlenca:Common: Injection site reactions, nausea, fatigue Serious: Immune reconstitution syndrome, hepatotoxicity
Sunosi:Common: Headache, nausea, decreased appetite, anxiety, insomnia Serious: Hypertension, tachycardia, psychiatric symptoms
Monitoring Parameters
Sunlenca:- HIV viral load and CD4 count
- Liver function tests
- Injection site reactions
- Signs of immune reconstitution syndrome
- Blood pressure and heart rate regularly
- Psychiatric symptoms
- Renal function in patients with renal impairment
- Signs of misuse or abuse
Patient Education
Sunlenca:- Importance of adherence to oral loading dose
- Understanding the long-acting nature of treatment
- Recognition of injection site reactions
- Signs of immune reconstitution syndrome
- Take medication upon awakening
- Avoid late-day dosing to prevent insomnia
- Regular blood pressure monitoring
- Report chest pain, palpitations, or psychiatric symptoms
- Potential for dependence with long-term use
- Avoid alcohol and other CNS depressants
References
1. FDA. Sunlenca (lenacapavir) prescribing information. 2022 2. FDA. Sunosi (solriamfetol) prescribing information. 2019 3. Segal-Maurer S, et al. Capsid Inhibition with Lenacapavir in Multidrug-Resistant HIV-1 Infection. N Engl J Med. 2022 4. Thorpy MJ, et al. A randomized study of solriamfetol for excessive sleepiness in narcolepsy. Ann Neurol. 2019 5. Schweitzer PK, et al. Solriamfetol for excessive sleepiness in obstructive sleep apnea. Am J Respir Crit Care Med. 2019 6. Clinical Pharmacology [Internet]. Tampa (FL): Elsevier. Updated periodically
Note: This information is intended for educational purposes only and should not replace clinical judgment. Always consult current prescribing information and clinical guidelines.