Essential Product Profile

In the UK, you'll primarily find this NNRTI antiretroviral as unbranded efavirenz since Sustiva was discontinued. The current generic versions come in 600mg tablets for adults and smaller 50mg or 100mg capsules for paediatric use. Packaging typically involves either plastic bottles with child-resistant caps or blister packs containing 30-90 doses. Pediatric formulations allow opening capsules to mix contents with soft foods like yoghurt when swallowing whole is difficult. Healthcare providers select this WHO Essential Medicine for HIV treatment regimens where newer options aren't suitable.

Pharmacological Actions Simplified

Efavirenz belongs to non-nucleoside reverse transcriptase inhibitors that work distinctly from other HIV medications. Instead of mimicking DNA building blocks, it attaches directly to the reverse transcriptase enzyme. This action blocks HIV from converting its RNA into DNA - a critical step for viral replication. Peak drug concentration occurs 3-5 hours after swallowing, making bedtime dosing optimal to sleep through common dizziness side effects.

Taking these tablets on an empty stomach matters significantly. High-fat meals can unpredictably boost absorption by 50% or more. Your liver processes this medication through CYP3A4 and CYP2B6 enzymes, creating potential interactions with other drugs using these pathways. Genetic variations in CYP2B6 affect how individuals metabolise efavirenz - some may need dose adjustments. Approximately 80% exits through faeces and 14% through urine, with a long 40-55 hour half-life enabling convenient once-daily dosing.

Concurrent alcohol consumption should be strictly avoided as it amplifies central nervous system effects like drowsiness and impaired concentration.

Approved and Off-Label Uses

This NNRTI has specific EMA-approved applications for managing HIV infection:

• First-line HIV-1 treatment when combined with nucleoside reverse transcriptase inhibitors (NRTIs) like tenofovir/emtricitabine
• Emergency post-exposure prophylaxis following potential HIV exposure when preferred regimens aren't available

Certain patient populations require special consideration when prescribing:

Pregnancy: Not recommended during the first trimester due to risk of neural tube defects. Only considered in later pregnancy if no alternatives exist.

Children: Approved for patients as young as three months (≥3.5kg) using precise weight-based dosing calculations.

Elderly: Increased monitoring needed for neurological side effects like confusion or dizziness.

Off-label applications in UK clinical practice include salvage protocols for multi-drug resistant HIV, typically combined with boosted protease inhibitors. One key limitation: efavirenz lacks effectiveness against HIV-2 infections. Monotherapy isn't recommended as it promotes viral resistance.

Sustiva Dosage Protocol and Adjustments

For adults with HIV, the standard Sustiva dose is 600mg taken once daily at bedtime, combined with other antiretroviral medicines. Taking it at night helps minimise potential side effects like dizziness. Timing matters - administer on an empty stomach either one hour before eating or two hours afterwards, as food significantly increases absorption.

Weight-Based Dosing for Children

Essential Dose Modifications

Liver impairment requires cautious use since the medication is processed by the liver. Patients with mild to moderate cirrhosis typically maintain standard dosage, though treatment is avoided in severe cases. Renal impairment doesn't usually necessitate adjustments as Sustiva doesn't rely on kidney function for elimination. Important drug interactions alter dosing - Sustiva reduces voriconazole levels, while high-dose ritonavir increases efavirenz concentration, requiring dose modifications supervised by HIV consultants.

Sustiva Administration and Storage

Swallow Sustiva tablets whole with water without food in your system. Food increases absorption by up to 50%, which can intensify side effects. For children struggling with swallowing, 50mg or 100mg capsules may be opened and contents mixed with a teaspoon of soft food like yogurt, although the 600mg tablet must never be split.

• Missed doses: Take immediately upon remembering unless within 8 hours of the next scheduled dose. Doubling up increases risks of severe reactions
• Accidental overdose: Symptoms include extreme agitation, uncoordinated movements, and hallucinations - seek urgent medical care if suspected

Storage requires keeping tablets at room temperature (15-30°C) in their original container away from light and moisture. When travelling, never keep medications in vehicle glove compartments where temperature fluctuates. Shelf life remains approximately two years from manufacturing when stored properly.

Sustiva Contraindications and Critical Warnings

Certain situations completely prohibit Sustiva use due to severe risks. Key contraindications include allergic reactions to efavirenz and dangerous interactions with specific medications:

Drug Combinations to Avoid

Concurrent use with hepatitis C medications containing elbasvir/grazoprevir may cause treatment failure. Sustiva reduces effectiveness of certain antifungals like voriconazole while boosting concentrations of sedatives such as midazolam. Other prohibited combinations include ergot derivatives for migraines and psychiatric drug pimozide.

Black Box Safety Alerts

Regulators mandate prominent warnings for serious potential complications:

• Psychiatric reactions: Severe depression, suicidal thoughts or aggressive behaviour reported particularly during initial weeks of treatment - monitor mood changes carefully
• Pregnancy risks: First-trimester exposure linked to birth defects including spinal cord abnormalities - contraception essential during and after treatment
• Liver injury: Potentially fatal hepatitis requires immediate discontinuation if symptoms like yellow skin develop

Additional precautions apply for those with co-existing hepatitis B or C, requiring regular liver function tests. Pre-existing seizure disorders necessitate discussion with specialists as treatment may lower seizure thresholds. Cholesterol levels should be monitored as efavirenz often raises LDL and triglycerides.

Understanding Sustiva Side Effects

Around one in four people experience dizziness when starting Sustiva (efavirenz). Insomnia affects roughly 16% of users, while headaches and nausea occur in 15% and 10% of cases respectively. Many report these effects lessen after the first month of treatment.

Recognising Moderate Reactions

Skin rashes appear in up to 10% of patients - sun avoidance is recommended during this period. Other manageable effects include vivid dreams, unusual fatigue, and occasional vomiting. Most rashes resolve without stopping treatment unless severe blistering or peeling occurs.

Serious Health Risks

Though rare (affecting less than 1% of users), Sustiva carries potentially severe risks requiring immediate medical attention. Discontinue use immediately if you experience thoughts of self-harm or notice signs of Stevens-Johnson syndrome (painful blisters on skin/mucous membranes). Liver enlargement with fatty infiltration constitutes another serious concern requiring prompt investigation.

Long-Term Considerations

Extended treatment may lead to body fat redistribution (lipodystrophy) or persistent neuropsychiatric issues like confusion or mood disorders. Cardiac rhythm abnormalities (QT prolongation) necessitate periodic monitoring via ECG.

Managing Reactions Effectively

Notify your care team immediately about skin changes or mood disturbances. Mild rashes often improve with topical treatments or antihistamines. Avoid operating vehicles or machinery during early treatment due to dizziness risk.

Real-World Patient Experiences

A snapshot of UK patient reports reveals both successes and challenges. Many share positive outcomes like viral suppression within six months, though significant numbers describe intense adjustment periods.

Treatment Experiences

"Kept me undetectable for eight years now," notes one user while others highlight disruptive side-effects: "Those waking nightmares made the first fortnight unbearable". Reports confirm psychiatric impacts including vivid dreams lasting several weeks before diminishing.

Medication Adherence Barriers

Dizziness and nausea contribute significantly to treatment gaps - studies indicate 22% of users missed doses due to these effects. Social stigma remains problematic, with many concealing medications at workplaces or educational settings.

Practical Coping Strategies

• Synchronise doses with daily routines like brushing teeth
• Set phone alarms for consistent timing
• Begin treatment on Friday evenings to sleep through initial dizziness

Shifting Treatment Preferences

Growing numbers of UK patients transition to integrase inhibitors like dolutegravir seeking reduced central nervous system effects. Clinicians increasingly consider newer alternatives first unless cost constraints necessitate Sustiva.