Cardura
| Noun | 1. | Cardura - an antihypertensive drug (trade name Cardura) that works by relaxing blood vessels so that blood passes through them more easily; it is also used to treat benign prostatic hyperplasia |
Cardura
doxazosin mesylate
Pharmacologic class: Sympatholytic, peripherally acting antiadrenergic
Therapeutic class: Antihypertensive
Pregnancy risk category C
Action
Blocks alpha1-adrenergic receptors, promoting vasodilation. Also reduces urethral resistance, relieving obstruction and improving urine flow and other symptoms of benign prostatic hypertrophy (BPH).
Availability
Tablets: 1 mg, 2 mg, 4 mg, 8 mg
Tablets (extended-release): 4 mg, 8 mg
Indications and dosages
➣ Hypertension
Adults: 1 mg P.O. once daily. May increase dosage gradually q 2 weeks, up to 2 to 16 mg daily, as needed.
➣ BPH
Adults: 1 mg P.O. once daily. May increase dosage gradually, up to 8 mg daily, as needed. Or, initially 4 mg (extended-release) P.O. daily. May increase dosage to 8 mg daily, as needed, at 3- to 4-week intervals.
Off-label uses
• Pheochromocytoma
• Syndrome X
Contraindications
• Hypersensitivity to drug, its components, or quinazoline derivatives
Precautions
Use cautiously in:
• renal or mild or moderate hepatic impairment, coronary insufficiency, or preexisting severe GI narrowing
• severe hepatic impairment (extended-release form not recommended)
• intraoperative floppy iris syndrome
• concurrent use of strong CYP3A4 inhibitor (such as atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, or voriconazole), phosphodiesterase-5 (PDE-5) inhibitors
• elderly patients
• pregnant or breastfeeding patients (extended-release form not recommended in breastfeeding patients)
• children (safety not established).
Administration
• Give initial immediate-release dose at bedtime to minimize orthostatic hypotension and syncope.
• Give initial extended-release dose at breakfast.
• Be aware that extended-release tablets aren't indicated for hypertension.
• Be aware that prostate carcinoma should be ruled out before giving drug for BPH.
• Know that incidence of orthostatic hypotension increases greatly when daily dosage exceeds 4 mg and that it usually occurs within 6 hours of administration.
See If new or worsening signs or symptoms of angina pectoris occur, discontinue drug.
Adverse reactions
CNS: dizziness, vertigo, headache, depression, drowsiness, fatigue, nervousness, weakness, asthenia
CV: orthostatic hypotension, chest pain, palpitations, tachycardia, arrhythmias
EENT: abnormal or blurred vision, conjunctivitis, epistaxis, rhinitis, pharyngitis
GI: nausea, vomiting, diarrhea, constipation, abdominal discomfort, flatulence, dry mouth
GU: decreased libido, sexual dysfunction
Respiratory: dyspnea
Musculoskeletal: joint pain, arthritis, gout, myalgia
Skin: flushing, rash, pruritus
Other: edema
Interactions
Drug-drug. Clonidine, nitrates, other antihypertensives: decreased antihypertensive effect
Drugs that reduce GI motility leading to markedly prolonged GI retention times (such as anticholinergics): increased systemic exposure to doxazosin
PDE-5 inhibitors: increased risk of symptomatic hypotension
Drug-diagnostic tests. Neutrophils, white blood cells: decreased counts
Drug-food. Any food: increased drug plasma Cmax (extended-release form)
Patient monitoring
• Monitor blood pressure with patient lying down and standing up every 2 to 6 hours after initial dose or after a dosage increase (when orthostatic hypotension is most likely to occur).
Patient teaching
• Tell patient to swallow extended-release tablets whole and not to chew, divide, cut, or crush them.
• Caution patient not to drive or perform other activities requiring alertness for 12 to 24 hours after first dose.
• Tell patient to move slowly when sitting up or standing, to avoid dizziness or light-headedness from sudden blood pressure decrease.
• Advise patient to report episodes of dizziness or palpitations.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.
doxazosin
(dox-ay-zoe-sin) doxazosin,Cardura
(trade name),Cardura XL
(trade name)Classification
Therapeutic: antihypertensivesPharmacologic: peripherally acting antiadrenergics
Indications
Action
Therapeutic effects
Pharmacokinetics
Time/action profile
| ROUTE | ONSET | PEAK | DURATION |
|---|---|---|---|
| PO† | 1–2 hr | 2–6 hr | 24 hr |
| PO-XL‡ | 5 wk | unknown | unknown |
Contraindications/Precautions
Adverse Reactions/Side Effects
Central nervous system
- dizziness (most frequent)
- headache (most frequent)
- depression
- drowsiness
- fatigue
- nervousness
- weakness
Ear, Eye, Nose, Throat
- abnormal vision
- blurred vision
- conjunctivitis
- epistaxis
- intraoperative floppy iris syndrome
Respiratory
- dyspnea
Cardiovascular
- first-dose orthostatic hypotension (most frequent)
- arrhythmias
- chest pain
- edema
- palpitations
Gastrointestinal
- abdominal discomfort
- constipation
- diarrhea
- dry mouth
- flatulence
- nausea
- vomiting
Genitourinary
- ↓ libido
- priapism
- sexual dysfunction
Dermatologic
- flushing
- rash
- urticaria
Musculoskeletal
- arthralgia
- arthritis
- gout
- myalgia
Interactions
Drug-Drug interaction
↑ risk of hypotension with sildenafil, tadalafil, vardenafil, other antihypertensives, nitrates, or acute ingestion of alcohol.NSAIDs, sympathomimetics, or estrogens may ↓ effects of antihypertensive therapy.Route/Dosage
HypertensionAvailability (generic available)
Nursing implications
Nursing assessment
- Monitor BP and pulse 2–6 hr after first dose, with each increase in dose, and periodically during therapy. Report significant changes.
- Assess for first-dose orthostatic hypotension and syncope. Incidence may be dose related. Observe patient closely during this period and take precautions to prevent injury.
- Monitor intake and output ratios and daily weight, and assess for edema daily, especially at beginning of therapy. Report weight gain or edema.
- BPH: Assess patient for symptoms of prostatic hyperplasia (urinary hesitancy, feeling of incomplete bladder emptying, interruption of urinary stream, impairment of size and force of urinary stream, terminal urinary dribbling, straining to start flow, dysuria, urgency) prior to and periodically during therapy.
Potential Nursing Diagnoses
Impaired urinary elimination (Indications)Risk for injury (Side Effects)
Implementation
- Do not confuse Cardura with Coumadin.
- Oral: Administer daily dose at bedtime.
- XL tablets should be swallowed whole; do not break, crush, or chew.
- Hypertension: May be administered concurrently with a diuretic or other antihypertensive.
Patient/Family Teaching
- Emphasize the importance of continuing to take this medication, even if feeling well. Instruct patient to take medication at the same time each day. Take missed doses as soon as remembered unless almost time for next dose. Do not double doses.
- May cause drowsiness or dizziness. Advise patient to avoid driving or other activities requiring alertness until response to medication is known.
- Caution patient to change positions slowly to decrease orthostatic hypotension. May cause syncopal episodes, especially within first 24 hr of therapy, with dose increase, and with resumption of therapy after interruption.
- Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to avoid concurrent use of alcohol or OTC medications and herbal products, especially cold preparations, without consulting health care professional, especially cough, cold, or allergy remedies.
- Advise male patient to notify health care professional if priapism or erection of longer than 4 hr occurs; may lead to permanent impotence if not treated.
- Advise female patient to notify health care professional if pregnancy is planned or suspected or if breast feeding.
- Emphasize the importance of follow-up visits to determine effectiveness of therapy.
- Hypertension: Instruct patient and family on proper technique for BP monitoring. Advise them to check BP at least weekly and report significant changes.
- Encourage patient to comply with additional interventions for hypertension (weight reduction, low-sodium diet, smoking cessation, moderation of alcohol consumption, regular exercise, and stress management).
Evaluation/Desired Outcomes
- Decrease in BP without appearance of side effects.
- Decrease in urinary symptoms of BPH.
Cardura
(kär-do͝or′ə)Cardura®
Doxazosin mesylate, see there.Cardura
- noun
Synonyms for Cardura
noun an antihypertensive drug (trade name Cardura) that works by relaxing blood vessels so that blood passes through them more easily
Synonyms
- doxazosin
Related Words
- antihypertensive
- antihypertensive drug