Names and pronunciation
(da-ree-fen′ah-sin) Enablex
PDF page 354
Loading InternPractice…
Drug reference
(da-ree-fen′ah-sin) Enablex
PDF page 354
Func. class.: Antispasmodic/GU anticholinergic
PDF page 354
Chem. class.: M3 selective receptor antagonist
PDF page 354
Do not confuse: Enablex/Effexor XR
PDF page 354
ACTION: Bladder smooth muscle relaxation by decreasing the action of muscarinic receptors, thereby relieving overactive bladder
PDF page 354
USES: Urge incontinence, frequency, urgency in overactive bladder
PDF page 354
CONTRAINDICATIONS: Hyper- sensitivity, urinary retention, narrow- angle glaucoma (uncontrolled) Precautions: Severe hepatic disease (Child-Pugh C), GI/GU obstruction, con- trolled narrow-angle glaucoma, ulcerative colitis, myasthenia gravis, moderate hepatic disease (Child-Pugh B), elderly
PDF pages 354, 355
SIDE EFFECTS CNS: Dizziness, headache, confusion, hallucinations, drowsiness EENT: Blurred vision, dry eyes GI: Constipation, dry mouth, nausea, dyspepsia INTEG: Rash, pruritus, skin drying MISC: Angioedema, flulike symptoms
PDF page 355
INTERACTIONS Increase: level of—digoxin Increase: anticholinergic effect— anticholinergics Increase: darifenacin level—CYP3A4 and CYP2D6 inhibitors (ketoconazole, itraconazole, ritonavir) Increase: levels of—drugs metabolized by CYP2D6 (flecainide, tricyclics)
PDF page 355
DOSAGE AND ROUTES • Adult: PO 7.5 mg/day, initially; may in- crease to 15 mg/day after 14 days if needed With CYP3A4 inhibitor • Adult: PO max 7.5 mg/day Hepatic dosage • Adult: PO (Child-Pugh B) max 7.5 mg/ day; do not use in severe hepatic disease
PDF page 355
Available forms: Tablets, extended release 7.5, 15 mg
PDF page 355
Administer: • Without regard to meals; do not crush, break, chew extended-release tablets • Store at room temperature
PDF page 355
Assess: • Urinary function: urgency, frequency, retention, incontinence in bladder out- flow obstruction • Bowel pattern: constipation, abdomi- nal pain, increase fluids, bulk in diet if constipation occurs • Pregnancy/breastfeeding: no well- controlled studies; use only if benefit outweighs fetal risk; cautious use in breastfeeding, excretion is unknown
PDF page 355
Evaluate: • Therapeutic response: decreasing ur- gency, frequency of urination
PDF page 355
CLINICAL CONSIDERATIONS
PDF page 355
Patient and caregiver information: • To take without regard to meals; not to D crush, break, chew extended-release tab- lets; not to use other products unless approved by prescriber • Not to double or skip doses, provide “Patient Information” and ask to read • To discuss with provider all OTC, Rx, herbals, supplements used • To store at room temperature • To avoid breastfeeding; to notify pre- scriber if pregnancy is planned or suspected • About anticholinergic symptoms (dry mouth, constipation, dry eyes, heat pros- tration); not to become overheated • To avoid hazardous activities until re- action is known; dizziness, blurred vision can occur • Angioedema: to report facial swelling, difficulty swallowing, or large tongue
PDF page 355
PHARMACOKINETICS Peak 7 hr, half-life 12-19 hr, extensively metabolized by CYP2D6, less metabolism in poor metabolizers; some metabo- lism by CYP3A4, protein binding 98%, duration 24 hr
PDF page 355
• Adult: PO 7.5 mg/day, initially; may in- crease to 15 mg/day after 14 days if needed With CYP3A4 inhibitor
PDF page 355
• Adult: PO max 7.5 mg/day Hepatic dosage
PDF page 355
• Adult: PO (Child-Pugh B) max 7.5 mg/ day; do not use in severe hepatic disease
PDF page 355