Guanfacine

Labels ADHD monotherapy or adjunct to stimulants; supporting efficacy studies and dose limits concern children/adolescents ages 6–17. Below-six efficacy/safety are unestablished. This profile does not supply an adult ADHD evidence claim or a geriatric ADHD regimen.

Selected IR tablets manage hypertension alone or with antihypertensives, especially thiazide diuretics. The IR label does not recommend under-twelve use because evidence is unestablished. Off-label IR ADHD/tic/sleep regimens are excluded.

Start 1 mg once daily morning or evening at the same time; increase no more than 1 mg/week by response/tolerance. Target 0.05–0.12 mg/kg/day, generally 1–7 mg/day. Above 4 mg/day was not evaluated in ages 6–12; above 7 mg/day not evaluated in ages 13–17. Adjunctive stimulant trials did not study above 4 mg/day. Swallow whole; do not crush/chew/break or take with high-fat meals.

Start 1 mg once daily at bedtime to reduce somnolence. If inadequate after three to four weeks, 2 mg may be used. Higher doses were used but adverse effects rise significantly above 3 mg/day; this wording is not a universal ER or formal IR absolute maximum. Adjust cautiously to response.

To switch IR to Intuniv, discontinue IR and titrate ER; never substitute mg-for-mg. After at least two consecutive missed ER doses, consider retitration by tolerance. When discontinuing ER, reduce by no more than 1 mg every three to seven days and monitor BP/pulse. IR also warns against abrupt cessation but provides no identical universal numeric taper; individualize with the prescriber.

Selected ER contraindicates hypersensitivity to Intuniv, its ingredients or another guanfacine product. IR lists guanfacine hydrochloride hypersensitivity. Bradycardia/conduction/organ risks are warnings requiring individualized selection, not invented universal formal contraindications.

Neither selected product has a boxed warning. Serious rebound hypertension, syncope/conduction effects and sedation still warrant counseling and monitoring.

Common ER reactions include somnolence, fatigue/lethargy, hypotension, nausea, abdominal symptoms, dizziness and bradycardia depending on trial. IR commonly reports dry mouth, sedation, weakness, dizziness, constipation and sexual dysfunction. Postmarketing reports include rash, hallucinations and rebound-related events; rates across formulations/trials are not equivalent.

With a strong/moderate inhibitor, decrease ER to half the recommended target; after stopping inhibitor return toward the recommended target. Strong/moderate inducers may require up to twice the recommended target; adding an inducer calls for adjustment over one to two weeks, and stopping one calls for decrease to target over one to two weeks. These changes are supervised by response/tolerance, not a blanket doubling for every patient.

CNS depressants add sedation; antihypertensive/heart-rate-lowering/sympatholytic agents add hypotension or conduction risk. IR reports reduced exposure with enzyme inducers such as phenytoin/phenobarbital but does not supply the ER half/double numeric algorithm. Small negative interaction studies do not prove universal compatibility; review all medicines.

Current ER data over infrequent pregnancy use have not identified a risk signal but do not establish zero risk; IR retains limited-controlled-study wording. Discuss the ADHD pregnancy registry when relevant. Human milk/infant data are absent; animal milk transfer is documented. If breastfeeding exposure occurs, monitor infant sedation, lethargy/poor feeding and possible low BP/bradycardia while weighing maternal need and feeding benefits.

ER evidence ages 6–17 and age-specific dose limits differ from IR under-twelve nonrecommendation. ER geriatric safety/efficacy are unestablished; IR older-adult information is limited and low-end dosing is prudent. No adult/pediatric cross-formulation efficacy equivalence is asserted.

ER may need dose reduction with significant renal/hepatic impairment; no numeric threshold/percentage table is supplied. Pediatric organ PK has not been assessed. IR advises low-end renal dosing; its poor-dialysis-removal wording does not create a universal ER dialysis regimen. Both require attention to BP/sedation and organ comorbidity.

Guanfacine is a central alpha-2A agonist and is not a CNS stimulant. Reduced sympathetic impulses lower vascular resistance/heart rate; the precise ADHD therapeutic mechanism is unknown.

Approximately 70% is protein bound and CYP3A4 metabolism is important. ER peak is about five hours in pediatric ADHD; IR peak is around one to four hours. Mean half-life is roughly sixteen to eighteen hours in studied adults. ER has lower peak/total exposure and delayed peak relative to equal-mg IR; high-fat food increases ER exposure. Renal and hepatic elimination matter and dialysis clears little.

Monitor efficacy, BP/pulse, orthostatic symptoms and alertness; reassess ER weight-based dosing as the child grows. Swallow ER whole, avoid high-fat meals/alcohol and obtain advice after repeated missed doses or vomiting. Use the written taper; monitor during reduction. Seek assessment for syncope or severe rebound symptoms and review pregnancy/feeding plans.

Seek medical/Poison Control assessment. Early hypertension may precede delayed hypotension, bradycardia, lethargy or respiratory depression. ER labeling advises observing lethargic children/adolescents for more serious delayed toxicity up to twenty-four hours. Poor dialysis removal and historical tolerated cases do not establish a safe extra dose; no home lavage/reversal protocol is supplied.

ER example

Intuniv 1 mg white/off-white round; 503 / 1 mg

ER package

Bottle 100 · NDC 54092-513-02

IR example

Amneal 1 mg white oval; AN / 711

IR package

Bottle 100 · NDC 53746-711-01

Selected Intuniv ER has 1, 2, 3 and 4 mg tablets; higher total daily regimens may involve multiple tablets. Selected IR has 1 and 2 mg guanfacine-equivalent tablets. Other products, liquids/compounds and crushing/tube protocols are not reviewed. ER tablets must remain intact.

Intuniv: 20–25°C, excursions 15–30°C. Selected IR: 20–25°C in a tight light-resistant container with required child-resistant closure. Secure medicines from children and follow actual expiry; no compounded beyond-use date is supplied.