ONYDA XR
Clinical safety rating
cautionComprehensive clinical and safety monograph for ONYDA XR (ONYDA XR).
Clonidine is a central alpha-2 adrenergic agonist that stimulates alpha-2 adrenergic receptors in the brainstem, reducing sympathetic outflow from the CNS, resulting in decreased peripheral resistance, renal vascular resistance, heart rate, and blood pressure.
| Metabolism | Clonidine is metabolized primarily in the liver via cytochrome P450 (CYP) enzymes, mainly CYP2D6, to inactive metabolites. |
| Excretion | Primarily renal (60–70% as unchanged drug) and biliary/fecal (20–30% as metabolites). |
| Half-life | Terminal elimination half-life of 28–35 hours; accumulation occurs with daily dosing, reaching steady state in 5–7 days. |
| Protein binding | 99% bound to plasma proteins (primarily alpha-1-acid glycoprotein and albumin). |
| Volume of Distribution | Vd approximately 3–4 L/kg, indicating extensive extravascular distribution and tissue binding. |
| Bioavailability | Oral: 100% (immediate-release); extended-release (ONYDA XR): 87% relative to immediate-release due to first-pass metabolism. |
| Onset of Action | Oral: 30–60 minutes to detectable plasma levels; clinical effect (e.g., pain relief) within 1–2 hours. |
| Duration of Action | Duration of analgesic effect: 8–12 hours; extended-release formulation provides sustained plasma levels for 24 hours with once-daily dosing. |
| Molecular Weight | 390.44 |
Onyda XR (clonidine hydrochloride extended-release tablets) 0.17 mg orally once daily at bedtime.
| Dosage form | SUSPENSION, EXTENDED RELEASE |
| Renal impairment | For GFR <30 mL/min, initiate at 0.17 mg once daily; titrate cautiously. Not studied in dialysis. |
| Liver impairment | No specific adjustment in Child-Pugh A or B; use caution in severe impairment (Child-Pugh C). |
| Pediatric use | Not Approved for pediatric patients; safety and efficacy not established. |
| Geriatric use | Start at low end of dosing range (0.17 mg) due to increased sensitivity and renal function decline. |
| 1st trimester | Contraindicated: pregnancy category X based on animal studies showing teratogenicity and fetal harm. |
| 2nd trimester | Contraindicated: carries risk of fetal harm; no adequate studies in pregnant women. |
| 3rd trimester | Contraindicated: may cause fetal harm when administered to a pregnant woman. |
Clinical note
Comprehensive clinical and safety monograph for ONYDA XR (ONYDA XR).
| Placental transfer | Not studied in humans; animal studies indicate placental transfer occurs. |
| Breastfeeding | Excretion into human milk is unknown; due to potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account importance of drug to mother. |
| Lactation Rating | L5 (Contraindicated) |
| Teratogenic Risk | FDA Pregnancy Category C. First trimester: limited data; animal studies show fetal abnormalities at high doses. Second/third trimester: risk of premature closure of fetal ductus arteriosus and oligohydramnios due to NSAID component (clonidine is not a major teratogen). Avoid after 30 weeks gestation. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate regularly. Fetal ultrasound for amniotic fluid index and ductus arteriosus patency if used beyond 20 weeks. Assess fetal growth and well-being. |
| Fertility Effects | Clonidine may impair fertility in males and females based on animal studies (altered reproductive cycles, decreased sperm count). Human data are limited. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
PregnancyHypersensitivity to any component
| Precautions | Rebound hypertension upon abrupt discontinuation, Central nervous system depression (drowsiness, sedation), Bradycardia and heart block, Orthostatic hypotension, Use with caution in patients with severe coronary insufficiency, recent myocardial infarction, cerebrovascular disease, or chronic renal failure |
| Food/Dietary | Grapefruit and grapefruit juice may increase clonidine levels (potential interaction); advise avoidance or caution. Alcohol can enhance CNS depression and hypotensive effects; avoid concurrent use. No significant food interactions reported; take with or without food. |
| Clinical Pearls | ONYDA XR (clonidine hydrochloride extended-release) is a centrally acting alpha-2 adrenergic agonist indicated for attention deficit hyperactivity disorder (ADHD) as monotherapy or adjunctive therapy to stimulants. Avoid abrupt discontinuation to prevent rebound hypertension. Monitor heart rate and blood pressure regularly; bradycardia and orthostatic hypotension may occur. Use with caution in patients with renal impairment (dose adjustment needed for creatinine clearance <30 mL/min). Can cause QTc prolongation; avoid concurrent use with other QTc-prolonging drugs. Tablets must be swallowed whole; do not crush, chew, or split. |
| Patient Advice | Take exactly as prescribed, usually once daily in the morning; do not crush or chew the extended-release tablet. · Do not stop taking suddenly; abrupt discontinuation can cause rapid increase in blood pressure, anxiety, and agitation. · Avoid alcohol and sedatives as they can increase drowsiness and dizziness. · Stand up slowly from sitting or lying positions to prevent fainting from low blood pressure. · Inform your doctor if you have kidney problems, heart disease, or a history of fainting; dose adjustments may be needed. |
Loading safety data…