At 25-100 mg pre-bed (sleep dose for non-depressed users):

• Onset: 30-60 min; many users describe a heavy-eyelid, slowing-of-thought feel within 45 min. Tmax ~1-2 hr (food modestly delays).
• Peak (1-3 hr): Strong sedation. Easy to fall asleep but not amnestic like zolpidem — most users have intact memory of the period before sleep, distinct from the "I did what?" Z-drug pattern.
• Mid-night maintenance: Mixed. Half-life ~3-9 hr means in some users effect tapers in the early morning hours and they wake before alarm; in others sleep maintenance is the strongest signal. Empirically the most common positive report is fewer middle-of-night awakenings, consistent with the meta-analysis WASO finding.
• Morning: Mild residual hangover is typical — heavier-headed than placebo/baseline, not as severe as Z-drug or benzodiazepine hangover for most. Subjectively reported as "groggy for the first hour, then clears." Worse at 100 mg than 50 mg, and worse in the first 1-2 weeks before adaptation. A meaningful subset of users (~10-20%) cannot get past this morning fog and discontinue.
• Sleep architecture experience: Users report "deep" sleep and vivid dreams (REM preserved) — distinct from Z-drug "lights out, no dreams" feel.
• Orthostatic effect: Standing up too fast in the morning (or middle-of-night bathroom trip) → dizziness, occasional pre-syncope. Worst in the first week. Falls risk is a real downside, especially in the elderly.
• Dry mouth, mild dizziness, occasional nausea common in week 1.

Honest variability: Trazodone is one of the more polarized sleep drugs. For some users it's a perfect 50 mg "knock me out gently and let me have my mornings back" — and they happily take it for years. For others the m-CPP makes them feel anxious or weird and they hate it from dose 1. Pharmacogenomics (CYP2D6 PM/IM) likely explains a substantial share of the variance.

Important — paradoxical reactions:

• Anxiety / agitation / akathisia-like jitter at first dose in some users (m-CPP). Stops on discontinuation. Predicts intolerance.
• Priapism (see Side effects) — rare but emergency, uncorrelated with subjective experience.

• Tolerance buildup: Slow but present. Subjective sleep effect commonly described as "ceiling" — works at 50 mg for months/years but doesn't deepen, and some users report needing to increase dose or switch over time.
• Dependence (psychological): Common with chronic nightly use as a "sleep crutch" — not classical pharmacological dependence (no withdrawal seizures, no DEA scheduling) but the behavioral pattern of "I can't sleep without it" develops, similar to other sleep meds.
• Recommended cycle: No formal cycling needed; PRN use is standard.
• Reset protocol: Slow taper (1-2 weeks) if discontinuing after >4 weeks of nightly use.

Synergistic with

• None of practical relevance for Dylan's profile. For depressed patients, trazodone is sometimes adjuncted to an SSRI for sleep-disturbed MDD — but this is depression treatment, not the sleep use case.
• Magnesium glycinate (already V4): NMDA modulation + glycinergic relaxation, mechanistically independent of trazodone. Safe co-admin if trazodone were used.
• Apigenin (already V4): GABA-A PAM at low doses. Mechanistically independent. Safe co-admin.

Avoid stacking with

• MAOIs (selegiline at antidepressant doses, phenelzine, tranylcypromine, isocarboxazid, moclobemide, linezolid, methylene blue): ABSOLUTE contraindication — serotonin syndrome risk. 14-day washout each direction. Selegiline at low MAO-B-selective doses (1-2.5 mg) is unlikely to cross into clinically dangerous MAO-A inhibition but the labeling is conservative — avoid combo with selegiline if Dylan ever onboards selegiline (V5+ optional).
• SSRIs / SNRIs / tricyclics: caution — serotonin syndrome risk increases, additive QTc, additive sedation. Trazodone + bupropion is a known prescriber combo for sleep-disturbed depression but not for healthy users.
• Strong CYP3A4 inhibitors (clarithromycin, ketoconazole, itraconazole, ritonavir, nefazodone, grapefruit juice in large quantities): trazodone exposure rises, m-CPP rises more (CYP3A4 produces it), QTc burden increases. Avoid or reduce dose substantially.
• Strong CYP3A4 inducers (carbamazepine, phenytoin, rifampin, St. John's wort, efavirenz): trazodone exposure drops, m-CPP balance shifts. Avoid.
• Other α1 antagonists (prazosin, doxazosin, terazosin, tamsulosin, antipsychotics with α1 activity): additive priapism risk + additive orthostatic hypotension. Strong avoid.
• QT-prolonging drugs (ondansetron, azithromycin, fluoroquinolones, methadone, Class 1A/3 antiarrhythmics, quetiapine, ziprasidone, citalopram >40 mg, hydroxyzine high-dose): additive QTc — avoid stack or ECG monitor.
• Z-drugs / benzodiazepines / opioids / alcohol: additive sedation and respiratory depression. Avoid double-stacking hypnotics.
• Modafinil: Pharmacokinetically interactive (modafinil mildly induces CYP3A4 → could shift trazodone/m-CPP balance) and functionally counterproductive (waking + sleeping drugs same calendar day with timing overlap). Not a hard contraindication if modafinil is dosed AM and trazodone HS, but trazodone in Dylan's V5 modafinil context isn't recommended.
• Bupropion: lowers seizure threshold; trazodone same. Combo possible but elevated seizure risk if both at high doses.
• Mirtazapine: Both 5-HT2A antagonists with sedation; additive sedation + additive α1 (mirtazapine is also α2-blocking). Combo not standard. Case reports of priapism in trazodone+mirtazapine combo even when each tolerated alone (PMC 3583761).

Neutral / safe co-administration

• Most non-CNS medications: no significant interaction.
• DHA / fish oil, NAC, citicoline, PS, curcumin, rhodiola, D3+K2, vitamin C, beta-alanine, creatine, l-tryptophan, l-theanine — no documented interactions with trazodone.
• Caffeine — pharmacologically opposite but not contraindicated. Functionally counterproductive if dosed near bedtime.

Trazodone is primarily a CYP3A4 substrate (m-CPP formation); CYP2D6 hydroxylates m-CPP for clearance. The CYP3A4/CYP2D6 ratio determines parent vs metabolite exposure — relevant for both efficacy and side effect (m-CPP-mediated anxiety) prediction.

• Strong CYP3A4 inhibitors: increase parent trazodone AND m-CPP. Dose reduction recommended.
• Strong CYP3A4 inducers: decrease parent and shift balance. May render sub-therapeutic.
• CYP2D6 inhibitors (fluoxetine, paroxetine, bupropion, quinidine, terbinafine): m-CPP accumulates → anxiety/dizziness/QTc risk increases.
• CYP2D6 PMs (genetic): higher m-CPP/trazodone ratios; QTc and dizziness signals correlate with PM phenotype.
• Grapefruit juice: moderate CYP3A4 inhibition. Avoid same-day at trazodone dosing.
• No clinically significant impact on hormonal contraception.
• Renal impairment: modest accumulation; no specific dose adjustment.
• Hepatic impairment: caution; trazodone is hepatically cleared.

• CYP2D6 phenotype is the primary pharmacogenomic axis. Poor metabolizers (PMs, ~7-10% of Caucasians) accumulate higher m-CPP/trazodone ratios → higher rates of dizziness, anxiety, and QTc prolongation correlated with PM phenotype (Recurrence of Serotonin Toxicity / Cytochrome 2D6, Psychiatrist.com; Ferdinande 2024 hepatotoxicity case). Ultra-rapid metabolizers (UMs) clear m-CPP fast but may also clear parent metabolites differently — net effect on response variable.
• CYP3A4*22 carriers: reduced enzyme activity → potentially higher trazodone exposure but lower m-CPP formation (since CYP3A4 produces m-CPP). Net effect ambiguous.
• CYP3A5*3: most non-Africans are *3/*3 non-expressors; CYP3A4 dominates clearance.
• 23andMe raw data check (Dylan, June 2026): if CYP2D6 PM/IM → predicted higher m-CPP exposure, predicted intolerance to trazodone. Already a strong reason to deprioritize trazodone for Dylan vs cleaner alternatives that don't have m-CPP issues at all.
• No HLA-class associations of clinical relevance reported.

For Dylan: sourcing is irrelevant — verdict is do-not-use. If a future scenario flips the verdict, US Rx generic via telehealth or primary care is trivial.

Baseline (before starting, if forced into use)

• ECG (12-lead) for QTc — especially if any concomitant QT-prolonging drugs, cardiac history, or family history of sudden cardiac death.
• Orthostatic BP delta (supine vs standing 1-min, 3-min) — establishes baseline before drug.
• ALT / AST — hepatic baseline (CYP3A4 load).
• Sleep diary 14 days minimum: sleep onset, wake time, awakenings, morning alertness 0-10.
• Insomnia Severity Index (ISI) — 7-question validated tool.
• Epworth Sleepiness Scale.
• CYP2D6 phenotype (23andMe raw or pharmacogenomic panel) — predicts m-CPP exposure and intolerance risk.

During use

• Morning alertness 0-10 every morning — single most important Dylan-relevant biomarker if trazodone is ever onboarded. Brain-priority means morning fog disqualifies the drug even if sleep itself improves.
• Sleep diary continued through trial period (4-6 weeks minimum to declare success/fail).
• Orthostatic symptom log — any standing-up dizziness, especially mornings and middle-of-night.
• Erection duration log (males) — any erection >1 hr unprovoked is a warning sign; >4 hr is ER.
• Wearable sleep stage data (REM%, N3%, fragmentation) — Colmi R06 or similar.
• ECG (repeat) at 4-6 weeks if QT-prolonging stack changes or palpitations occur.

Post-cycle (if discontinuing after >4 weeks)

• Track sleep diary 2 weeks post-taper for rebound insomnia (mild but real).
• Orthostatic BP should normalize within days.