Decongestants increase the resistance to urine flow through the prostate by causing the smooth muscle in the prostate to squeeze the urethra, and antihistamines weaken the bladder contractions. This lessens the bladder’s ability to expel the urine.
The ability to urinate normally depends upon having a forceful bladder muscle contraction to expel the urine and a low resistance to the flow of urine through the prostate gland and out the urethra. Anything that weakens the bladder’s ability to contract or increases the resistance to urine flow out of the bladder makes it more difficult—and sometimes impossible—to empty the bladder.
Which antihistamines should you choose?
Antihistamines block the histamine receptor that triggers many allergic reactions. Antihistamines are also commonly used to treat runny nose, sneezing and nasal congestion associated with a common cold and flu symptoms. Often, they are combined with decongestants in over-the-counter preparations.
The newer second- and third- generation antihistamines, such as loratadine (Alavert, Claritin), cetirizine (Zyrtec) and fexofenadine (Allegra) cause less drowsiness and have fewer adverse effects on bladder contractions. Thus, they do not carry a prostate warning.
What is BPH?
Approximately 80% of men develop benign enlargement of the prostate gland after the age of 50 (called benign prostatic hyperplasia or BPH). The lower urinary tract symptoms (LUTS) of BPH include decreased forcefulness of the urinary stream, slow urination, urinary frequency, urinary urgency, having to get up frequently at night and the complete inability to urinate, called urinary retention, which requires insertion of a tube (catheter) through the urethra for relief.
The older, firstgeneration antihistamines, such as diphenhydramine (Benadryl, Nytol, Sominex), brompheniramine (Dimetapp), chlorpheniramine (Chlor-Trimeton) and doxylamine (Vicks NyQuil, Alka-Seltzer Plus) are effective in relieving allergic symptoms. However, they cause drowsiness and weaken the ability of the bladder to expel urine. The drowsiness itself may allow a man to sleep through the signal to urinate, which can allow the bladder to become overdistended and contribute to acute urinary retention. The first-generation antihistamines contain a warning for men with prostate disease.
Both types of antihistamines frequently are mixed with pain relievers or decongestants and can cause urinary difficulties.
Decongestant nasal sprays for cold relief can cause increased urinary problems in men with BPH because they increase the resistance to urine flow through the prostate gland.
If you are a man with BPH and allergies, colds or the flu, treat only the symptoms that you have: runny nose, sneezing, etc. If you do not need both an antihistamine and a decongestant, just take the medicine you need.
Vapor rubs using topical preparations containing camphor, menthol, eucalyptus and other aromatic oils may be applied to the neck and chest at bedtime or vaporized in a machine during sleeping hours. There is some evidence (marginal at best) that the use of aroma therapy can help relieve symptoms of the common cold. Vapor therapy does not cause urinary difficulties.
Take only the amount of medicine recommended. Do not exceed the recommended frequency. Do not use more than one cold/flu medicine at a time. If you are taking other drugs, ask your physician whether it is safe for you to also take an over-the-counter cold/flu remedy.