Dosing & Uses
Dosage Forms & Strengths
capsule
- 1mg
- 2mg
- 5mg
- 10mg
Benign Prostate Hyperplasia
Initial: 1 mg PO qHS
May gradually increase to 5 mg PO qHS; up to 20 mg/day beneficial for some
Dosing considerations
- Give first dose and subsequent increases at bedtime to avoid syncope
- May take with food
Hypertension
Initial: 1 mg PO qHS
Maintenance: 1-5 mg/day or q12hr; may increase to ≤20 mg/day
Dosing considerations
- Give first dose and subsequent increases at bedtime to avoid syncope
- May take with food
Dosing Modifications
Hepatic impairment: Use with caution
Dosage Forms & Strengths
capsule
- 1mg
- 2mg
- 5mg
- 10mg
Hypertension (Off-label)
1 mg/day PO; increase dose gradually as necessary; up to maximum of 20 mg/day
Hypertension
Initial: 0.5 mg PO qHS and titrate to response
Dosing considerations
Avoid use for hypertension; high risk of orthostatic hypotension (Beers criteria)
May cause significant orthostatic hypotension and syncope
Lower initial doses than those used for nongeriatric adults, as well as gradual adjustments, are recommended for hypertension
Give first dose and subsequent increases at bedtime to avoid syncope
Adverse effects such as dry mouth and urinary complications can be bothersome in the elderly
May take with food
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (5)
- lofexidine
lofexidine, terazosin. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration with other drugs that decrease pulse or blood pressure to mitigate risk of excessive bradycardia and hypotension.
- sildenafil
sildenafil increases effects of terazosin by pharmacodynamic synergism. Avoid or Use Alternate Drug. Risk of hypotension; separate sildenafil >25mg from alpha blocker by 4hr.
- tamsulosin
terazosin, tamsulosin. Either increases effects of the other by additive vasodilation. Avoid or Use Alternate Drug. Risk of hypotension.
- vardenafil
vardenafil increases effects of terazosin by pharmacodynamic synergism. Contraindicated. Risk of hypotension.
- yohimbe
yohimbe increases effects of terazosin by pharmacodynamic synergism. Contraindicated.
Monitor Closely (92)
- acebutolol
terazosin and acebutolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. Additive hypotensive effects may occur when terazosin is used in combination with acebutolol.
- aceclofenac
aceclofenac decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- acemetacin
acemetacin decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- aldesleukin
aldesleukin increases effects of terazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.
- alfuzosin
alfuzosin and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- amifostine
amifostine, terazosin. 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.
- amlodipine
terazosin and amlodipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- asenapine
asenapine and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- aspirin
aspirin decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- aspirin rectal
aspirin rectal decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- aspirin/citric acid/sodium bicarbonate
aspirin/citric acid/sodium bicarbonate decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- atenolol
terazosin and atenolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- avanafil
avanafil increases effects of terazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.
- benazepril
benazepril, terazosin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- betaxolol
terazosin and betaxolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- bisoprolol
terazosin and bisoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- bretylium
terazosin, bretylium. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Each drug may cause hypotension.
- captopril
captopril, terazosin. 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.
- carbidopa
carbidopa increases effects of terazosin 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.
- carvedilol
terazosin and carvedilol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- celecoxib
celecoxib decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- celiprolol
terazosin and celiprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- choline magnesium trisalicylate
choline magnesium trisalicylate decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- clevidipine
terazosin and clevidipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- diclofenac
diclofenac decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- diflunisal
diflunisal decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- diltiazem
terazosin and diltiazem both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- doxazosin
doxazosin and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- enalapril
enalapril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- esmolol
terazosin and esmolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. Additive hypotensive effects may occur when terazosin is used in combination with esmolol.
- etodolac
etodolac decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- felodipine
terazosin and felodipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- fenoprofen
fenoprofen decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- flurbiprofen
flurbiprofen decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- fosinopril
fosinopril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- ibuprofen
ibuprofen decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- ibuprofen IV
ibuprofen IV decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- iloperidone
iloperidone increases effects of terazosin by pharmacodynamic synergism. Use Caution/Monitor.
- imidapril
imidapril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- indomethacin
indomethacin decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- isradipine
terazosin and isradipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- ketoprofen
ketoprofen decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- ketorolac
ketorolac decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- ketorolac intranasal
ketorolac intranasal decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- labetalol
terazosin and labetalol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- levodopa
levodopa increases effects of terazosin by pharmacodynamic synergism. Use Caution/Monitor. Consider decreasing dosage of antihypertensive agent.
- lisinopril
lisinopril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- lornoxicam
lornoxicam decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- lurasidone
lurasidone increases effects of terazosin 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.
- maraviroc
maraviroc, terazosin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Increased risk of orthostatic hypotension.
- meclofenamate
meclofenamate decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- mefenamic acid
mefenamic acid decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- meloxicam
meloxicam decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- methylphenidate
methylphenidate will decrease the level or effect of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. Methylphenidate may diminish antihypertensive effects. Monitor BP.
- metoprolol
terazosin and metoprolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- moexipril
moexipril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- moxisylyte
moxisylyte and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- nabumetone
nabumetone decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- nadolol
terazosin and nadolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- naproxen
naproxen decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- nebivolol
terazosin and nebivolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- nicardipine
terazosin and nicardipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- nifedipine
terazosin and nifedipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- nisoldipine
terazosin and nisoldipine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- nitroglycerin rectal
nitroglycerin rectal, terazosin. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Observe for possible additive hypotensive effects during concomitant use. .
- oxaprozin
oxaprozin decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- oxymetazoline topical
oxymetazoline topical increases and terazosin decreases sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- parecoxib
parecoxib decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- penbutolol
terazosin and penbutolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- perindopril
perindopril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- phenoxybenzamine
phenoxybenzamine and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- phentolamine
phentolamine and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- pindolol
terazosin and pindolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- piroxicam
piroxicam decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- prazosin
prazosin and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- propranolol
terazosin and propranolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. Additive hypotensive effects may occur when terazosin is used in combination with propranolol.
- pseudoephedrine
pseudoephedrine decreases effects of terazosin by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- quinapril
quinapril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- ramipril
ramipril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- salicylates (non-asa)
salicylates (non-asa) decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- salsalate
salsalate decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- silodosin
silodosin and terazosin both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- sotalol
terazosin and sotalol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely. Additive hypotensive effects may occur when terazosin is used in combination with sotalol.
- sulfasalazine
sulfasalazine decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- sulindac
sulindac decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- tadalafil
tadalafil increases effects of terazosin by pharmacodynamic synergism. Use Caution/Monitor. Risk of hypotension.
- timolol
terazosin and timolol both increase anti-hypertensive channel blocking. Modify Therapy/Monitor Closely.
- tolfenamic acid
tolfenamic acid decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- tolmetin
tolmetin decreases effects of terazosin by pharmacodynamic antagonism. Use Caution/Monitor. NSAIDs decrease prostaglandin synthesis.
- trandolapril
trandolapril, terazosin. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Exaggerated first dose hypotensive response.
- verapamil
terazosin and verapamil both increase anti-hypertensive channel blocking. Use Caution/Monitor.
- zotepine
terazosin and zotepine both increase anti-hypertensive channel blocking. Use Caution/Monitor.
Minor (7)
- brimonidine
brimonidine increases effects of terazosin by pharmacodynamic synergism. Minor/Significance Unknown.
- butcher's broom
terazosin, butcher's broom. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- ethanol
terazosin, ethanol. Mechanism: pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension, esp. in Asian pts.
- phenylephrine
terazosin, phenylephrine. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- phenylephrine PO
terazosin, phenylephrine PO. Either decreases effects of the other by Mechanism: pharmacodynamic antagonism. Minor/Significance Unknown.
- tizanidine
tizanidine increases effects of terazosin by pharmacodynamic synergism. Minor/Significance Unknown. Risk of hypotension.
- treprostinil
treprostinil increases effects of terazosin by pharmacodynamic synergism. Minor/Significance Unknown.
Adverse Effects
>10%
Dizziness (10-20%)
Asthenia (2-13%)
1-10%
Hypotension (3-7%)
Rhinitis/nasal congestion (2-6%)
Lightheadedness (3-5%)
Somnolence (3-5%)
Palpitation (4%)
Nausea (2-4%)
Edema (3%)
Sinusitis (3%)
Dyspnea (2-3%)
Fatigue (2.5%)
Headache (2.5%)
Back pain (2.4%)
Flulike syndrome (2.4%)
Tachycardia (2%)
Amblyopia (1-2%)
Blurred vision (1-2%)
Impotence (1-2%)
Syncope (1%)
Warnings
Contraindications
Hypersensitivity to terazosin, other quinazolines
Cautions
Carcinoma of the prostate and BPH cause many of the same symptoms; these two diseases frequently co-exist; patients thought to have BPH should be examined prior to starting therapy to rule out presence of carcinoma of the prostate
Therapy can cause marked lowering of blood pressure, especially postural hypotension, and syncope in association with first dose or first few days of therapy; a similar effect can be anticipated if therapy is interrupted for several days and then restarted; to decrease likelihood of syncope or excessive hypotension, treatment should always be initiated at a low dose (1 mg) and increased slowly; additional antihypertensive agents should be added with caution; patient should be cautioned to avoid situations, such as driving or hazardous tasks, where injury could result should syncope occur during initiation of therapy
If syncope occurs, the patient should be placed in a recumbent position and treated supportively as necessary; there is evidence that orthostatic effect is greater, even in chronic use, shortly after dosing; the risk of the events is greatest during initial seven days of treatment, but continues at all time intervals
While syncope is the most severe orthostatic effect, other symptoms of lowered blood pressure, such as dizziness, lightheadedness and palpitations, are more common; patients with occupations in which such events represent potential problems should be treated with particular caution
May cause CNS depression, which may impair physical or mental abilities; use caution when performing tasks that may require mental alertness, including driving or operating heavy machinery
May exacerbate heart failure
Concomitant administration with PDE-5 inhibitor (eg, sildenafil) can result in additive blood pressure-lowering effects and symptomatic hypotension; initiate PDE-5 inhibitor therapy at lowest dose
Risk of priapism (rare); because this condition can lead to permanent impotence if not promptly treated, patients must be advised about seriousness of the condition
Pregnancy & Lactation
Pregnancy category: C
Lactation: Not known if excreted into breast milk; use caution
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Blocks postsynaptic alpha-1 receptor; alpha blockade causes arterial and venous dilation
Selective agents cause less tachycardia than do nonselective agents
Absorption
Bioavailability: 90%
Onset (hypertension): 3 hr
Onset (benign prostate hyperplasia): 2 weeks
Duration: 24 hr
Peak response (benign prostate hyperplasia): 4-6 weeks
Peak plasma time: 1 hr
Distribution
Protein bound: 90-94%
Vd: 25-30 L
Metabolism
Metabolized extensively via hydrolysis, O-demethylation, and N-dealkylation in liver
Metabolites: 6- and 7-O-demethyl terazosin, piperazine derivative, diamine metabolite
Elimination
Half-life: 9-12 hr
Renal clearance: 9-12.5 mL/min
Excretion: Feces (55-60%); urine (40%)
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| terazosin oral - | 5 mg capsule |  | |
| terazosin oral - | 2 mg capsule |  | |
| terazosin oral - | 10 mg capsule |  | |
| terazosin oral - | 1 mg capsule |  | |
| terazosin oral - | 5 mg capsule |  | |
| terazosin oral - | 1 mg capsule |  | |
| terazosin oral - | 10 mg capsule |  | |
| terazosin oral - | 10 mg capsule |  | |
| terazosin oral - | 2 mg capsule |  | |
| terazosin oral - | 5 mg capsule |  | |
| terazosin oral - | 2 mg capsule |  | |
| terazosin oral - | 1 mg capsule |  | |
| terazosin oral - | 2 mg capsule |  | |
| terazosin oral - | 10 mg capsule |  |
Copyright © 2010 First DataBank, Inc.
Formulary
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