ANTIHISTAMINES,DECONGESTANTS, AND ANTICHOLINERGICS (Systemic)?

Some commonly used brand names are:

In the U.S.?

• AH-chew ¹
• D.A. Chewable ¹
• Dallergy ¹
• Dura-Vent/DA ¹
• Extendryl ¹
• Extendryl JR ¹
• Extendryl SR ¹
• Mescolor ²
• OMNIhist L.A. ¹
• Stahist ³

? Not commercially available in Canada.

Category

• Antihistaminic (H ₁-receptor)-decongestant-anticholinergic?Chlorpheniramine, Phenylephrine, and Methscopolamine

Description

Antihistamine, decongestant, and anticholinergic combinations are usedto treat the nasal congestion (stuffy nose) and runny nose caused by allergiesand/or the common cold.

Antihistamines work by preventing the effects of a substance called histamine,which is produced by the body. Histamine can cause itching, sneezing, runnynose, and watery eyes. The antihistamine contained in these combinations ischlorpheniramine.

The decongestants in these combinations, phenylephrine, and pseudoephedrineproduce a narrowing of blood vessels. This leads to clearing of nasal congestion,but it may also cause an increase in blood pressure in patients who have highblood pressure.

Anticholinergics, such as atropine, hyoscyamine, methscopolamine, andscopolamine may help produce a drying effect in the nose and chest.

These combinations are available only with your doctor's prescription inthe following dosage forms:

• Chlorpheniramine, Phenylephrine, and Methscopolamine
  • Extended-release capsules (U.S.)
  • Syrup (U.S.)
  • Tablets (U.S.)
  • Chewable tablets (U.S.)
  • Extended-release tablets (U.S.)
• Chlorpheniramine, Pseudoephedrine, and Methscopolamine
  • Extended-release tablets (U.S.)

Before Using This Medicine

In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For antihistamine, decongestant,and anticholinergic combinations, the following should be considered:

Allergies?Tell your doctor if you have ever had any unusual orallergic reactions to antihistamines or anticholinergics, or to amphetamine,dextroamphetamine (e.g., Dexedrine), ephedrine (e.g., Ephed II), epinephrine(e.g., Adrenalin), isoproterenol (e.g., Isuprel), metaproterenol (e.g., Alupent),methamphetamine (e.g., Desoxyn), norepinephrine (e.g., Levophed), phenylephrine(e.g., Neo-Synephrine), pseudoephedrine (e.g., Sudafed), or terbutaline (e.g.,Brethine). Also, tell your health care professional if you are allergic toany other substances, such as foods, preservatives, or dyes.

Pregnancy?For the individual ingredients of these combinations,the following apply:

• Antihistamines?Antihistamines havenot been shown to cause problems in humans.
• Atropine?Studies on effects in pregnancyhave not been done in humans. Atropine has not been shown to cause birth defectsor other problems in animals.
• Hyoscyamine?Studies on effects inpregnancy have not been done in either humans or animals.
• Methscopolamine?Studies on effectsin pregnancy have not been done in either humans or animals.
• Phenylephrine?Studies on birth defectshave not been done in either humans or animals.
• Pseudoephedrine?Studies on birthdefects have not been done in humans. Pseudoephedrine has not been shown tocause birth defects in animal studies. However, studies in animals have shownthat pseudoephedrine causes a reduction in average weight, length, and rateof bone formation in the animal fetus.
• Scopolamine?Studies on effects inpregnancy have not been done in pregnant women. However, studies in animalsat doses many times the human dose have shown that scopolamine causes a smallincrease in the number of fetal deaths.

Breast-feeding?Small amounts of antihistamines, decongestants,and anticholinergics may pass into the breast milk. Use is not recommendedsince this medicine may cause side effects, such as unusual excitement orirritability, in the nursing baby. Also, since this medicine tends to decreasethe secretions of the body, it is possible that the flow of breast milk maybe reduced in some women.

Children?Very young children are usually more sensitive thanadults to the effects of this medicine. Increases in blood pressure, nightmaresor unusual excitement, nervousness, restlessness, or irritability may be morelikely to occur in children. Also, when anticholinergics are given to childrenduring hot weather, a rapid increase in body temperature may occur, whichmay lead to heat stroke. In infants and children, especially those with spasticparalysis or brain damage, this medicine may be especially likely to causesevere side effects.

Older adults?Confusion or memory loss, difficult and painful urination,dizziness, drowsiness, dryness of mouth, or convulsions (seizures) may bemore likely to occur in the elderly, who are usually more sensitive than youngeradults to the effects of this medicine. Also, nightmares or unusual excitement,nervousness, restlessness, or irritability may be more likely to occur inelderly patients. In addition, eye pain may occur, which may be a sign ofglaucoma.

Other medicines?Although certain medicines should not be usedtogether at all, in other cases different medicines may be used together evenif an interaction might occur. In these cases, your doctor may want to changethe dose, or other precautions may be necessary. When you are taking thismedicine it is especially important that your health care professional knowif you are taking any of the following:

• Amantadine (e.g., Symmetrel) or
• Amphetamines or
• Appetite suppressants (diet pills), except fenfluramine (e.g., Pondimin),or
• Beta-adrenergic blocking agents (acebutolol [e.g., Sectral], atenolol[e.g., Tenormin], betaxolol [e.g., Kerlone], bisoprolol [e.g., Zebeta], carteolol[e.g., Cartrol], labetalol [e.g., Normodyne], metoprolol [e.g., Lopressor],nadolol [e.g., Corgard], oxprenolol [e.g., Trasicor], penbutolol [e.g., Levatol],pindolol [e.g., Visken], propranolol [e.g., Inderal], sotalol [e.g., Sotacor],timolol [e.g., Blocadren]) or
• Caffeine (e.g., NoDoz) or
• Chlophedianol (e.g., Ulone) or
• Cocaine or
• Digitalis medicine (heart medicine) or
• Medicine for asthma or other breathing problems or
• Medicine for colds, sinus problems, or hay fever or other allergies(including nose drops or sprays) or
• Methylphenidate (e.g., Ritalin) or
• Nabilone (e.g., Cesamet) or
• Pemoline (e.g., Cylert)?Using any of these medicines togetherwith a decongestant-containing combination may cause excessive stimulant sideeffects, such as difficulty in sleeping, heart rate problems, nervousness,and irritability

• Central nervous system (CNS) depressants?Using these combinationswith CNS depressants may worsen the effects (e.g., drowsiness) of CNS depressantsor antihistamines

• Monoamine oxidase (MAO) inhibitors (furazolidone [e.g., Furoxone],isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g.,Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate])?Takingan antihistamine, decongestant, and anticholinergic combination while youare taking or within 2 weeks of taking MAO inhibitors, may make the side effectsof the antihistamines, decongestants, and anticholinergics more severe; thesemedicines should not be used together

• Other anticholinergics (medicine for abdominal or stomach spasmsor cramps)?Side effects of antihistamines or anticholinergics, suchas dryness of mouth, may be more likely to occur

• Potassium chloride (e.g., Kay Ciel)?Using this medicine withan anticholinergic-containing medicine may make gastrointestinal problemscaused by potassium worse

• Rauwolfia alkaloids (alseroxylon [e.g., Rauwiloid], deserpidine [e.g.,Harmonyl], rauwolfia serpentina [e.g., Raudixin], reserpine [e.g., Serpasil])?Thesemedicines may increase or decrease the effect of the decongestant in thismedicine

• Tricyclic antidepressants (amitriptyline [e.g., Elavil], amoxapine[e.g., Asendin], clomipramine [e.g., Anafranil], desipramine [e.g., Pertofrane],doxepin [e.g., Sinequan], imipramine [e.g., Tofranil], nortriptyline [e.g.,Aventyl], protriptyline [e.g., Vivactil], trimipramine [e.g., Surmontil])?Effects,such as drowsiness, may be worsened; also, taking these medicines togethermay make some of the anticholinergic side effects, such as dryness of mouth,more severe

Other medical problems?The presence of other medicalproblems may affect the use of antihistamine, decongestant, and anticholinergiccombinations. Make sure you tell your doctor if you have any other medicalproblems, especially:

• Brain damage in children or
• Down syndrome or
• Dryness of mouth (severe and continuing) or
• Enlarged prostate or
• Fever or
• Glaucoma or
• Intestinal blockage or other intestinal problems or
• Kidney disease or
• Liver disease or
• Lung disease or
• Mental or emotional problems or
• Myasthenia gravis or
• Toxemia of pregnancy or
• Urinary tract blockage or difficult urination?These medicinesmay make these conditions worse

• Type 2 diabetes mellitus ?The decongestant in thismedicine may put diabetic patients at greater risk of having heart or bloodvessel disease

• Heart or blood vessel disease or
• High blood pressure?The decongestant and anticholinergic inthis medicine may cause the blood pressure to increase and may also speedup the heart rate

• Overactive thyroid?If the overactive thyroid has caused a fastheartbeat, the decongestant and anticholinergic in this medicine may causethe heart rate to speed up further

Proper Use of This Medicine

Take this medicine only as directed. Do not take more of it and donot take it more often than recommended on the label, unless otherwise directedby your doctor. To do so may increase the chance of side effects.

If this medicine irritates your stomach, you may take it with food or aglass of water or milk, to lessen the irritation.

For patients taking the extended-release capsule orextended-release tablet form of this medicine:

• Swallow the capsule or tablet whole.
• Do not crush, break, or chew before swallowing.
• If the capsule is too large to swallow, you may mix the contentsof the capsule with applesauce, jelly, honey, or syrup and swallow withoutchewing.

Dosing?The dose of these combination medicines willbe different for different patients. Follow your doctor'sorders or the directions on the label. The following information includesonly the average doses for these combinations. If yourdose is different, do not change it unless your doctor tells you todo so.

The number of capsules or tablets or teaspoonfuls of syrup that you takedepends on the strength of the medicine. Also, the number of doses you takeeach day and the time between doses depend on whether you are taking a short-actingor a long-acting form of this medicine.

• For regular (short-acting) dosage forms(syrup, tablets, or chewable tablets):
  • For allergy and cold symptoms:
    • Adults and children 12 years of age and older?1 or 2 tabletsor chewable tablets, or 1 to 2 teaspoonfuls of syrup every four to six hours.
    • Children up to 6 years of age?Use and dose must be determinedby your doctor.
    • Children 6 to 12 years of age?1 chewable tablet or 1 teaspoonfulof syrup every four hours.
• For long-acting dosage forms (extended-releasecapsules or tablets):
  • For allergy and cold symptoms:
    • Adults and children 12 years of age and older?1 capsule ortablet every twelve hours.
    • Children up to 12 years of age?Use and dose must be determinedby your doctor.

Missed dose?If you miss a dose of this medicine, take it assoon as possible. However, if it is almost time for your next dose, skip themissed dose and go back to your regular dosing schedule. Do not double doses.

Storage?To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in otherdamp places. Heat or moisture may cause the medicine to break down.
• Keep the liquid form of this medicine from freezing.
• Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

Checkwith your doctor if your symptoms do not improve or become worse, or if youhave a high fever.

Before you have any skin tests for allergies, tell the doctor in chargethat you are taking this medicine. The results of the test may be affectedby the antihistamine in this medicine.

These medicines may make you sweat less, causing your body temperatureto increase. Use extra care not to become overheatedduring exercise or hot weather while you are taking this medicine,since overheating may result in heat stroke. Also hot baths or saunas maymake you dizzy or faint while you are taking this medicine.

The anticholinergic contained in this medicine may cause some people tohave blurred vision. Make sure your vision is clear beforeyou drive or do anything else that could be dangerous if you are not ableto see well. These medicines may also cause your eyes to become moresensitive to light than they are normally. Wearing sunglasses may help lessenthe discomfort from bright light.

These medicines may cause some people to become dizzy or drowsy. Make sure you know how you react to this medicine before youdrive, use machines, or do anything else that could be dangerous if you aredizzy or are not alert.

The decongestant in this medicine may cause some people to be nervous orrestless or to have trouble in sleeping. If you have trouble in sleeping, take the last dose of this medicine for each day a fewhours before bedtime. If you have any questions about this, check withyour doctor.

Before having any kind of surgery (including dental surgery) or emergencytreatment, tell the medical doctor or dentist in charge that you are takingthis medicine.

This medicine may cause dryness of the mouth, nose, and throat. For temporaryrelief, use sugarless candy or gum, melt bits of ice in your mouth, or usea saliva substitute. However, if your mouth continues to feel dry for morethan 2 weeks, check with your dentist. Continuing dryness of the mouth mayincrease the chance of dental disease, including tooth decay, gum disease,and fungus infections.

If you think you or someone else may have taken anoverdose, get emergency help at once. Taking an overdose of this medicineor taking this medicine with alcohol or other CNS depressants may lead tounconsciousness and possibly death.

Side Effects of This Medicine

Along with its needed effects,a medicine may cause some unwanted effects. Although not all of these sideeffects may occur, if they do occur they may need medical attention.

Get emergency help immediatelyif any of the following symptoms of overdose occur:

Clumsiness or unsteadiness; convulsions(seizures); drowsiness (severe); dryness of mouth, nose, or throat (severe); fastheartbeat; flushing or redness of face; hallucinations (seeing, hearing, or feeling things that are notthere); headache (continuing); shortness of breath or troubled breathing; troublein sleeping

For pseudoephedrine only

Also, check with your doctoras soon as possible if any of the following side effects occur:

Rare

Irregular or slow heartbeat; mood ormental changes; skin rash, hives, or itching; sore throat and fever; tightness inchest; unusual bleeding or bruising; unusual tiredness or weakness

Other side effects may occurthat usually do not need medical attention. These side effects may go awayduring treatment as your body adjusts to the medicine. However, check withyour health care professional if any of the following side effects continueor are bothersome:

More common

Drowsiness; nervousness; restlessness; thickening of mucus; trouble in sleeping

Less common?more common with high doses

Blurred vision; confusion; difficult or painful urination; dizziness; dryness of mouth, nose, or throat; fast or pounding heartbeat; headache; increased sweating; lossof appetite; nausea or vomiting; nightmares; ringing or buzzing in ears; trembling; unusual excitement, nervousness,restlessness, or irritability; unusual paleness; weakness

Other side effects not listed above may also occur in some patients. If younotice any other effects, check with your doctor.