Desvenlafaxine

Pristiq is indicated for major depressive disorder in adults. Pediatric efficacy/safety are not established and it is not approved for children; it is not approved for bipolar depression. Other anxiety, pain or menopausal indications and a preferred guideline treatment rank are outside this label-based profile.

Doses up to 400 mg/day were studied; this is not the recommended dose or a universal maximum-prescribing instruction. Above 50 mg/day no additional benefit was demonstrated, while adverse effects/discontinuation increased. When switching from another antidepressant, including venlafaxine, tapering of the previous medicine may be needed. Do not concurrently take other desvenlafaxine- or venlafaxine-containing products. Reassess ongoing treatment need periodically.

Wait at least 14 days after stopping a psychiatric MAOI before starting Pristiq; wait at least 7 days after stopping Pristiq before starting one. Do not initiate Pristiq during linezolid or IV methylene blue. If one of these is urgently necessary with no acceptable alternative, the label describes stopping Pristiq promptly under clinician supervision, monitoring serotonin symptoms for 7 days or until 24 hours after the last antimicrobial dose (whichever comes first), and restarting only ≥24 hours after its last dose. This is not a self-directed switch; other methylene-blue routes/doses have uncertain risk.

Hypersensitivity to desvenlafaxine succinate, venlafaxine hydrochloride or Pristiq excipients. Psychiatric MAOI co-use and the 7-day-after-Pristiq/14-day-after-MAOI windows are contraindicated. Starting Pristiq during linezolid or IV methylene blue is also contraindicated.

Short-term antidepressant studies showed increased suicidal thoughts/behaviors in children, adolescents and young adults; Pristiq is not approved for pediatric use. Monitor every patient for worsening and emergent suicidal symptoms, and involve caregivers in prompt reporting. Trial age comparisons do not remove the need for monitoring older adults or establish individual protection.

Common reactions include nausea, dizziness, insomnia, sweating, constipation, sleepiness, appetite reduction, anxiety and sexual effects. Trials reported lipid increases, proteinuria and orthostatic hypotension; serious postmarketing reports include Stevens–Johnson syndrome, acute pancreatitis and Takotsubo cardiomyopathy. Frequencies/causality of spontaneous reports are uncertain. Overdose experience is limited; the label also describes parent-venlafaxine arrhythmias, seizures, serotonin syndrome and fatal outcomes. Obtain emergency/Poison Help assessment; no specific Pristiq antidote is known.

Avoid prohibited MAOI combinations/windows. Other serotonergic medicines, including opioids, triptans, lithium, buspirone, amphetamines, other antidepressants and St. John’s wort, can increase serotonin-syndrome risk; clinically warranted combinations require counseling/monitoring. NSAIDs, aspirin, antiplatelets and anticoagulants increase bleeding risk. Avoid duplicating venlafaxine/desvenlafaxine products.

Label Table 8 says maintain the original CYP2D6-substrate dose with Pristiq ≤100 mg; at the studied 400 mg Pristiq dose, it describes reducing the substrate by up to half. This high-dose interaction observation does not recommend 400 mg treatment or supply a rule for every intermediate dose. Studied CYP3A4 or combined CYP2D6/CYP3A4 substrates needed no adjustment, not an exhaustive interaction guarantee. Avoid alcohol. False-positive urine immunoassays for PCP/amphetamines can persist after stopping; confirmatory specific testing can distinguish them.

Use the Cockcroft–Gault CrCl dose categories in Dosage; they are not silently replaced by laboratory eGFR. No extra dialysis dose. Moderate–severe hepatic impairment uses recommended 50 mg with no escalation above 100 mg/day. Older patients need assessment of reduced renal clearance, orthostatic hypotension and hyponatremia; no age-only dose multiplier is supplied.

No published Pristiq pregnancy studies were available to the label; much observational evidence concerns venlafaxine and cannot establish absence of risk. Weigh untreated depression and exposure risks. Mid/late-pregnancy use may increase preeclampsia risk, near-delivery use postpartum bleeding risk, and late exposure neonatal complications/discontinuation symptoms requiring observation. A pregnancy registry is available. Limited data show low milk levels without observed infant adverse reactions in a small study, but milk-production data are absent; individual feeding/maternal treatment assessment remains necessary.

Pristiq is not approved for pediatric patients. Trials in ages 7–17 did not establish efficacy and reported weight loss; similar adolescent exposure does not create an approved pediatric regimen. Antidepressant suicidality monitoring concerns still apply.

The antidepressant mechanism is not fully established; serotonin and norepinephrine reuptake inhibition is thought to enhance these transmitters in the CNS. Desvenlafaxine is the principal active metabolite of venlafaxine, with its own ER dose and label.

Absorption

Oral bioavailability about 80%; food has no meaningful AUC effect and dosing may be with/without food. Steady state approximately 4–5 days.

Binding

Approximately 30% plasma protein-bound.

Metabolism

Primarily UGT conjugation; minor CYP3A4 oxidative metabolism. CYP2D6 is not involved in its metabolic pathway.

Elimination

Approximately 45% excreted unchanged in urine within 72 hours; renal function determines dose limits.

Scope

Linear high-dose PK studies are not prescribing recommendations. No universal half-life or impairment exposure ratio is inferred from image-only figures.

Follow depressive symptoms/function, adherence, worsening/suicidality and bipolar/mania symptoms, especially early and during dose changes. Check/control baseline BP and monitor regularly; assess renal function for the labeled CrCl regimen, orthostatic symptoms, bleeding and sodium when risk/symptoms justify. Discuss sexual function and weight/appetite; lipid abnormalities may need clinical evaluation. The label does not mandate a universal visit/lab interval, depression-score target or ECG for every patient.

Take the whole ER tablet with fluid at the same time daily. Do not stop abruptly or independently switch with venlafaxine/MAOIs; contact the prescriber for a taper. Avoid alcohol and assess driving/machinery effects before hazardous activities. Report suicidal symptoms urgently, and seek urgent care for serotonin symptoms, severe allergy/rash or eye pain/visual changes. A tablet-like inert shell in stool can be expected after drug absorption; do not take an extra dose because of it. Discuss pregnancy/breastfeeding and every new medicine/supplement.

Ingredient / route

Desvenlafaxine 50 mg equivalent, supplied as 76 mg desvenlafaxine succinate · oral ER tablet.

Appearance / imprint

Light pink square-pyramid tablet; W over 50 on flat side.

Labeler / example NDC

Wyeth Pharmaceuticals, Pfizer subsidiary · 0008-1211-30, bottle of 30.

U.S. status

Prescription NDA021992; not a controlled substance.

25 mg

Tan square-pyramid tablet, W over 25; 38 mg succinate equivalent to 25 mg desvenlafaxine. NDC 0008-1210-30.

50 mg

Light pink, W over 50; 76 mg succinate equivalent to 50 mg desvenlafaxine.

100 mg

Reddish-orange, W over 100; 152 mg succinate equivalent to 100 mg desvenlafaxine. NDC 0008-1222-30.

Scope

Other salts/brands such as Khedezla, generic manufacturers and non-U.S. products require their own current label. This is not an immediate-release, liquid or tablet-cutting regimen.

Store selected Pristiq at 20–25°C, excursions 15–30°C. Retain the labeled container, keep away from children and verify strength on refill. The ER tablet must remain intact; an inert matrix may be visible after GI transit. No current local-stock inference is made.