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A Review of Two More Drugs For Erectile Dysfunction: Vardenafil (LEVITRA) And Tadalifil (CIALIS)

Worst Pills, Best Pills Newsletter article January, 2004

 

The Health Research Group’s Seven Year Rule

You should wait at least seven years from the date of release to take any new drug unless it is one of those rare “breakthrough” drugs that offers you a documented therapeutic advantage over older proven drugs. New drugs are tested in a relatively small number of people before being released, and serious adverse effects or life-threatening drug interactions may not be detected until the new drug has been taken by hundreds of...

 

The Health Research Group’s Seven Year Rule

You should wait at least seven years from the date of release to take any new drug unless it is one of those rare “breakthrough” drugs that offers you a documented therapeutic advantage over older proven drugs. New drugs are tested in a relatively small number of people before being released, and serious adverse effects or life-threatening drug interactions may not be detected until the new drug has been taken by hundreds of thousands of people. A number of new drugs have been withdrawn within their first seven years after release. Also, warnings about serious new adverse reactions have been added to the labeling of a number of drugs, or new drug interactions have been detected, usually within the first seven years after a drug’s release.

 

Vardenafil (LEVITRA) and tadalafil (CIALIS) join sildenafil (VIAGRA) as the second and third oral drugs approved by the Food and Drug Administration to treat erectile dysfunction.

All three drugs work the same way by inhibiting an enzyme known as phosphodiesterase type 5. Inhibition of this enzyme causes relaxation of smooth muscles and increased blood flow to the penis.

Many commonly used drugs can interfere with sexual function in both men and women, causing loss of libido, or can interfere with erection or ejaculation in men, or can delay or prevent orgasm in women. Drug-related adverse effects on sexual function may be difficult to distinguish from the effects of depression or disease, but most are reversible when drug use is stopped and sometimes when dosage is decreased. On this page, there is a list of 130 drugs that can cause sexual dysfunction.

Before deciding to use vardenafil, tadalafil, or sildenafil, have a thorough check-up to rule out any medical problems that could cause a correctable sexual dysfunction. Also, check the list of drugs that can cause sexual dysfunction accompanying this article, and if you are taking any of them ask your doctor if they are still needed at all, if the dosage can be reduced, or ask about alternative drugs that do not cause sexual dysfunction.

None of these drugs should be used in combination with the family of drugs known as nitrates, such as nitroglycerine, which are used to treat chest pain (angina). Using nitrates with vardenafil, tadalafil, or sildenafil can result in dizziness, fainting, or a heart attack or stroke. Below is a list of nitrate drugs that can interact with vardenafil, tadalafil, or sildenafil.

 

Drugs Containing Nitrates that Should Not be Used with Vardenafil, Tadalafil, or Sildenafil

Nitroglycerin-Containing Drugs:

Deponit; Minitran; Nitrek; Nitro-Bid; Nitrocine; Nitro-Derm; Nitro Disc; Nitro-Dur; Nitrogard; Nitroglycerin; Nitroglycerin T/R; Nitroglyn; Nitrol Ointment; Nitrolan; Nitrolingual Spray; Nitrong; Nitropar; Nitropress; Nitroprex; Nitro S.A.; Nitrospan; Nitrostat; Nitro-Trans System; Nitro Transdermal; Nitro-Time; Transderm-Nitro; Tridil.

Isosorbide Mononitrate-Containing Drugs:

Imdur; ISMO; Isosorbide Mononitrate; Monoket; Isosorbide Nitrate; Dilatrate-SR; Iso-bid; Isordil; Isordil Tembids; Isosorbide Dinitrate; Isosorbide Dinitrate LA; Sorbitrate; Sorbitrate SA.

Illicit Substances Containing Nitrates:

Amyl nitrate or nitrite that goes by various names, including “poppers” and butyl nitrate.

 

In general, vardenafil, tadalafil, and sildenafil also should not be used in combination with the alpha-blocker family of drugs which are used to treat high blood pressure and enlarged prostate (benign prostatic hyperplasia). These drugs include alfuzosin (UROXATRAL), doxazosin (CARDURA), prazosin (MINIPRESS) tamsulosin (FLOMAX), and terazosin (HYTRIN). Using alpha-blockers with these three erectile dysfunction drugs can cause a dangerously low blood pressure that could lead ultimately to a stroke or heart attack.

The professional product labeling, or package insert, for tadalafil says not to take the drug with alpha blockers other than tamsulosin. The professional labeling for sildenafil says that the drug should not be taken in a dose greater than 25 milligrams at the same time (within four hours) of a dose of any alpha blocker. We advise consumers to be more cautious than this and avoid these erectile dysfunction drugs if they are taking an alpha blocker.

A number of drugs can interact with vardenafil, tadalafil, and sildenafil to increase the amounts of the erectile dysfunction drugs in the body. These include erythromycin (ERYTHROCIN, EES), indinavir (CRIXIVAN), itraconazole (SPORANOX), ketoconazole (NIZORAL), and ritonavir (NORVIR). In addition, interactions are listed for grapefruit juice with tadalafil and for sildenafil with cimetidine (TAGAMET) in their respective professional product labeling.

There are a number of medical conditions in which vardenafil, tadalafil, and sildenafil should be used with caution, or not at all, because of the potential for an adverse outcome. These are:

  • heart problems such as angina, heart failure, irregular heartbeats, or a heart attack. Ask your doctor if it is safe for you to have sexual activity.
  • low blood pressure or high blood pressure that is not controlled
  • a stroke
  • liver problems
  • kidney problems or require dialysis
  • retinitis pigmentosa, a rare genetic (runs in families) eye disease
  • stomach ulcers
  • a bleeding problem, a deformed penis shape, or Peyronie’s disease
  • an erection that lasted more than 4 hours
  • blood cell problems such as sickle cell anemia, multiple myeloma, or leukemia

Vardenafil is unique among these three drugs in that there are precautions in the drug’s professional product labeling about a condition known as QTc interval prolongation. This is an abnormality in the heart’s electrical conduction that can lead to fatal heart rhythm disturbances.

The QT interval is the length of time it takes the ventricles (large chambers of the heart) to discharge and recharge electrically. The QTc interval is measured on an electrocardiogram (EKG or ECG) in milliseconds (msec); the subscript “c” indicates that the QT interval has been corrected for the patient’s heart rate. Prolongation of the QT interval can lead to heart rhythm disturbances (cardiac arrhythmias) such as torsade de pointes. Torsade de pointes is a French phrase that means “twisted point” and describes the appearance of this type of rhythm disturbance on the EKG tracing.

Men with congenital QT prolongation and those taking drugs for heart rhythm disturbances such as amiodarone (CORDARONE), procainamide (PROCANBID), quinidine (DURAQUIN, QUINAGLUTE DURA-TABS, QUNIDEX), and sotalol (BETAPACE) should not take vardenafil.

There are legitimate reasons for using the erectile dysfunction drugs when other causes of erectile dysfunction have been ruled out. However, when these drugs are used for recreational purposes by men who do not need them, the risks of the drugs always outweigh the benefits.

What You Can Do

Do not use vardenafil, tadalafil, or sildenafil with any of the interacting drugs listed above.

Before deciding to use any of these drugs, have a thorough medical check-up to rule out any medical problems that could cause a correctable sexual dysfunction. Also, check the list of drugs that can cause sexual dysfunction in both men and women and if you are taking any of them ask your doctor if they are still needed, if the dosage can be reduced, or ask about alternative drugs that do not cause sexual dysfunction.

Drugs That Can Cause Sexual Dysfunction

 

BRAND NAME

GENERIC NAME

Antibiotics and other anti-infective agents

 

Nizoral

ketoconazole

 

Tegison

etretinate

Anticholinergics

 

Banthine

methantheline

 

Bentyl

dicyclomine

 

Cantil

mepenzolate

 

Darbid

isopropamide

 

Ditropan

oxybutynin

 

Homapin

homatropine

 

Pamine

methscopolamine

 

Pathilon

tridihexethyl

 

Pro-Banthine

propantheline

 

Quarzan

clidinium

 

Robinul

glycopyrrolate

 

Tral

hexocyclium

 

Transderm-Scop       

scopolamine

 

Valpin

anisotropine

Cancer drugs

 

Intron A, Roferon-A

interferon alfa

 

Lupron

leuprolide

 

Nolvadex

tamoxifen

 

Rheumatrex Dose Pack

methotrexate

Eye drugs

 

Daranide

dichlorphenamide

 

Diamox

acetazolamide

 

Neptazane

methazolamide

Gastrointestinal drugs

 

Axid

nizatidine

 

Azulfidine

sulfasalazine

 

Pepcid

famotidine

 

Prilosec

omeprazole

 

Reglan

metoclopramide

 

Tagamet

cimetidine

 

Zantac

ranitidine

Heart and blood vessel drugs
Antianginal drugs

 

Adalat, Adalat CC, Procardia, Procardia XL

nifedipine

 

Calan SR, Covera-HS,Isoptin SR, Verelan

verapamil

 

Lanoxicaps, Lanoxin

digoxin

Antiarrhythmics

 

Cordarone

amiodarone

 

Mexitil

mexiletine

 

Norpace

disopyramide

Blood vessel dilators

 

Cerespan, Pavabid

papaverine

Cholesterol-lowering drugs

 

Atromid-S       

clofibrate

 

Lopid

gemfibrozil

High blood pressure drugs (beta-blockers)

 

Blocadren

timolol

 

Cartrol

carteolol

 

Coreg

carvedilol

 

Inderal, Inderal LA

propranolol

 

Kerlone

betaxolol

 

Levatol

penbutolol

 

Lopressor, Toprol XL

metoprolol

 

Normodyne, Trandate

labetalol

 

Tenormin

atenolol

 

Zebeta

bisoprolol

High blood pressure drugs (diuretics)

 

Esidrix, HydroDiuril

hydrochlorothiazide

 

Hygroton

chlorthalidone

 

Lozol

indapamide

 

Midamor

amiloride

High blood pressure drugs (other)

 

 

reserpine

 

Aldactone

spironolactone

 

Aldomet

methyldopa

 

Apresoline

hydralazine

 

Catapres

clonidine

 

Demser

metyrosine

 

Hylorel

guanadrel

 

Inversine

mecamylamine

 

Ismelin

guanethidine

 

Minipress

prazosin

 

Tenex

guanfacine

 

Wytensin

guanabenz

Mind-affecting drugs
Antidepressants

 

Asendin

amoxapine

 

Aventyl, Pamelor

nortriptyline

 

Desyrel

trazodone

 

Effexor

venlafaxine

 

Elavil

amitriptyline

 

Lexapro

escitalopram

 

Lithobid, Lithonate

lithium

 

Ludiomil

maprotiline

 

Luvox

fluvoxamine

 

Marplan

isocarboxazid

 

Nardil

phenelzine

 

Norpramin

desipramine

 

Parnate

tranylcypromine

 

Paxil

paroxetine

 

Prozac, Serafem

fluoxetine

 

Serzone

nefazodone

 

Sinequan

doxepin

 

Tofranil

imipramine

 

Vivactil

protriptyline

 

Zoloft

sertraline

Antipsychotics

 

Abilify

aripiprazole

 

Geodon

ziprasidone

 

Clozaril

clozapine

 

Haldol

haloperidol

 

Mellaril

thioridazine

 

Moban

molindone

 

Navane

thiothixene

 

Orap

pimozide

 

Prolixin

fluphenazine

 

Risperdal

risperidone

 

Serentil

mesoridazine

 

Stelazine

trifluoperazine

 

Taractan

chlorprothixene

 

Thorazine

chlorpromazine

 

Trilafon

perphenazine

 

Zyprexa

olanzapine

Barbiturates

 

Nembutal

pentobarbital

Tranquilizers

 

BuSpar

buspirone

 

Valium

diazepam

 

Xanax

alprazolam

Neurological drugs
Anticonvulsants

 

Dilantin

phenytoin

 

Tegretol

carbamazepine

 

Zarontin

ethosuximide

Antiparkinsonians

 

Larodopa

levodopa

 

Parlodel

bromocriptine

 

Permax

pergolide

Painkillers/narcotics

 

Aleve, Anaprox, Naprosyn

naproxen

 

Dolophine, Methadose

methadone

 

Indocin

indomethacin

 

Revia, Trexan

naltrexone

Other drugs

 

 

alcohol

 

 

amphetamines

 

 

cocaine

 

Antabuse

disulfiram

 

Danocrine

danazol

 

Depo-Testosterone    

testosterone

 

Diprivan

propofol

 

Fastin

phentermine

 

Intralipid

fat emulsion

 

Lioresal

baclofen

 

Mazanor, Sanorex

mazindol

 

Plegine

phendimetrazine

 

Proscar

finasteride

 

Synarel

nafarelin

 

Tenuate, Tepanil

diethylpropion