AdultPediatricGeriatricDosage Forms & Strengths tablet 1mg 2mg 4mg 8mg tablet, extended release 4mg 8mg Hypertension 1 mg PO qDay in AM or PM; may titrate by doubling daily dose up to 16 mg qDay based on blood pressure response; usual dosage range is 1-2 mg qDay; if therapy is discontinued for several days, initiate dose at 1 mg qDay and titrate using initial dosing regimen Extended release: Not indicated for hypertension Benign Prostatic Hyperplasia Immediate release: 1 mg PO qDay; may titrate by doubling daily dose at 1-2 week intervals to maximum 8 mg/day If therapy is discontinued for several days, initiate dose at 1 mg qDay and titrate using initial dosing regimen Extended release: 4 mg PO qDay; may titrate based on response and tolerability every 3-4 weeks to 8 mg PO qDay If therapy is discontinued for several days, initiate dose at 1 mg qDay and titrate using initial dosing regimen Dosing Modifications Hepatic impairment: Use with caution in mild-to-moderate hepatic dysfunction; do not use in severe impairment Renal impairment: Labeling from manufacturer does not provide dosage adjustment information Dosing Considerations Give first dose and increase at bedtime to avoid syncopeDosage Forms & Strengths tablet 1mg 2mg 4mg 8mg Hypertension (Off-label) Immediate release: 1-4 mg PO once daily in AM or PMHypertension Avoid use for hypertension; high risk of orthostatic hypotension (Beers criteria); if used, lower initial dosages and gradual adjustments are recommended Immediate release: 0.5-16 mg PO once daily in AM or PM Extended release: Not indicated for hypertension Benign Prostatic Hyperplasia Immediate release: 1-8 mg/day PO Extended release: 4 mg/day PO initially at breakfast; may be increased to no more than 8 mg/day POInteraction CheckerEnter a drug name and doxazosinNo Results No Interactions Found Interactions FoundContraindicatedSerious - Use AlternativeSignificant - Monitor CloselyMinorAll Interactions Sort By: SeverityName Contraindicated (0)Serious - Use Alternative (4)sildenafilsildenafil increases effects of doxazosin by pharmacodynamic synergism. Avoid or Use Alternate Drug. Risk of hypotension; separate sildenafil >25mg from alpha blocker by 4hr.tamsulosindoxazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.vardenafilvardenafil increases effects of doxazosin by pharmacodynamic synergism. Contraindicated. Risk of hypotension.yohimbeyohimbe increases effects of doxazosin by pharmacodynamic synergism. Contraindicated.Monitor Closely (92)acebutololdoxazosin and acebutolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.aceclofenacaceclofenac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.acemetacinacemetacin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.aldesleukinaldesleukin increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.alfuzosinalfuzosin and doxazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.amifostineamifostine, doxazosin. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.amlodipinedoxazosin and amlodipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.asenapineasenapine and doxazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.aspirinaspirin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.aspirin rectalaspirin rectal decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.aspirin/citric acid/sodium bicarbonateaspirin/citric acid/sodium bicarbonate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.atenololdoxazosin and atenolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.avanafilavanafil increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.betaxololdoxazosin and betaxolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.bisoprololdoxazosin and bisoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.captoprilcaptopril, doxazosin. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response. Both drugs lower blood pressure. Monitor blood pressure.carbidopacarbidopa increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Therapy with carbidopa, given with or without levodopa or carbidopa-levodopa combination products, is started, dosage adjustment of the antihypertensive drug may be required.carvediloldoxazosin and carvedilol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.celecoxibcelecoxib decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.celiprololdoxazosin and celiprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.choline magnesium trisalicylatecholine magnesium trisalicylate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.clevidipinedoxazosin and clevidipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.clonidineclonidine, doxazosin. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive sympatholytic action may worsen sinus node dysfunction and atrioventricular (AV) block.diclofenacdiclofenac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.diflunisaldiflunisal decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.diltiazemdoxazosin and diltiazem both increase anti-hypertensive channel blocking. Use Caution/Monitor.duvelisibduvelisib will increase the level or effect of doxazosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration with duvelisib increases AUC of a sensitive CYP3A4 substrate which may increase the risk of toxicities of these drugs. Consider reducing the dose of the sensitive CYP3A4 substrate and monitor for signs of toxicities of the coadministered sensitive CYP3A substrate.enalaprilenalapril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.esmololdoxazosin and esmolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.etodolacetodolac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.felodipinedoxazosin and felodipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.fenoprofenfenoprofen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.flurbiprofenflurbiprofen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.fosinoprilfosinopril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.ibuprofenibuprofen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.ibuprofen IVibuprofen IV decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.iloperidoneiloperidone increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor.imidaprilimidapril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.indomethacinindomethacin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.isradipinedoxazosin and isradipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.ketoprofenketoprofen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.ketorolacketorolac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.ketorolac intranasalketorolac intranasal decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.labetaloldoxazosin and labetalol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.levodopalevodopa increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Consider decreasing dosage of antihypertensive agent.lisinoprillisinopril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.lornoxicamlornoxicam decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.lurasidonelurasidone increases effects of doxazosin by Other (see comment). Use Caution/Monitor. Comment: Potential for increased risk of hypotension with concurrent use. Monitor blood pressure and adjust dose of antihypertensive agent as needed.maravirocmaraviroc, doxazosin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of orthostatic hypotension.meclofenamatemeclofenamate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.mefenamic acidmefenamic acid decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.meloxicammeloxicam decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.metoprololdoxazosin and metoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.moexiprilmoexipril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.moxisylytedoxazosin and moxisylyte both increase anti-hypertensive channel blocking. Use Caution/Monitor.nabumetonenabumetone decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.nadololdoxazosin and nadolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.naproxennaproxen decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.nebivololdoxazosin and nebivolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.nicardipinedoxazosin and nicardipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.nifedipinedoxazosin and nifedipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.nirmatrelvir/ritonavirnirmatrelvir/ritonavir will increase the level or effect of doxazosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor for increased bradycardia, hypotension, or dizziness. If needed, temporarily pause the antihypertensive drug. nisoldipinedoxazosin and nisoldipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.nitroglycerin rectalnitroglycerin rectal, doxazosin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Observe for possible additive hypotensive effects during concomitant use. .oxaprozinoxaprozin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.oxymetazoline topicaloxymetazoline topical increases and doxazosin decreases sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Effect of interaction is not clear, use caution. Use Caution/Monitor.parecoxibparecoxib decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.penbutololdoxazosin and penbutolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.perindoprilperindopril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.phenoxybenzaminedoxazosin and phenoxybenzamine both increase anti-hypertensive channel blocking. Use Caution/Monitor.phentolaminedoxazosin and phentolamine both increase anti-hypertensive channel blocking. Use Caution/Monitor.pindololdoxazosin and pindolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.piroxicampiroxicam decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.prazosindoxazosin and prazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.propranololdoxazosin and propranolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.pseudoephedrinepseudoephedrine decreases effects of doxazosin by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.quinaprilquinapril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.ramiprilramipril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.salicylates (non-asa)salicylates (non-asa) decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.salsalatesalsalate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.silodosindoxazosin and silodosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.sotaloldoxazosin and sotalol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.sulfasalazinesulfasalazine decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.sulindacsulindac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.tadalafiltadalafil increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.terazosindoxazosin and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.timololdoxazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.tolfenamic acidtolfenamic acid decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.tolmetintolmetin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.trandolapriltrandolapril, doxazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.verapamildoxazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.zotepinedoxazosin and zotepine both increase anti-hypertensive channel blocking. Use Caution/Monitor.Minor (7)brimonidinebrimonidine increases effects of doxazosin by pharmacodynamic synergism. Minor/Significance Unknown.butcher's broomdoxazosin, butcher's broom. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.ethanoldoxazosin, ethanol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension, esp. in Asian pts.phenylephrinedoxazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.phenylephrine POdoxazosin, phenylephrine PO. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.tizanidinetizanidine increases effects of doxazosin by pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension.treprostiniltreprostinil increases effects of doxazosin by pharmacodynamic synergism. Minor/Significance Unknown.acebutololMonitor Closely (1)doxazosin and acebutolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. The severity and duration of hypotension following the first dose of doxozosin may be enhanced.aceclofenacMonitor Closely (1)aceclofenac decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.acemetacinMonitor Closely (1)acemetacin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.aldesleukinMonitor Closely (1)aldesleukin increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.alfuzosinMonitor Closely (1)alfuzosin and doxazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.amifostineMonitor Closely (1)amifostine, doxazosin. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration with blood pressure lowering agents may increase the risk and severity of hypotension associated with amifostine. When amifostine is used at chemotherapeutic doses, withhold blood pressure lowering medications for 24 hr prior to amifostine; if blood pressure lowering medication cannot be withheld, do not administer amifostine.amlodipineMonitor Closely (1)doxazosin and amlodipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.asenapineMonitor Closely (1)asenapine and doxazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.aspirinMonitor Closely (1)aspirin decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.aspirin rectalMonitor Closely (1)aspirin rectal decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.aspirin/citric acid/sodium bicarbonateMonitor Closely (1)aspirin/citric acid/sodium bicarbonate decreases effects of doxazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.atenololMonitor Closely (1)doxazosin and atenolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.avanafilMonitor Closely (1)avanafil increases effects of doxazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.betaxololMonitor Closely (1)doxazosin and betaxolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.bisoprololMonitor Closely (1)doxazosin