Top 9 Pseudoephedrine Side Effects

Pseudoephedrine or PSE is a sympathomimetic drug belonging to the class of amphetamine and phenethylamine chemicals. Pseudoephedrine is found in several over the counter medications in combination with other drugs or as single ingredient. It is often combined with antihistamines, dextromethorphan, paracetamol (acetaminophen), guaifenesin or an NSAID.  Pseudoephedrine is readily reduced to methamphetamine. Pseudoephedrine is present as a plant alkaloid in Ephedra species (ma huang). However, PSE for commercial use is usually produced from the fermentation of dextrose with benzaldehyde. Its use is monitored because of its side effects and because of the potential in using it in the making of illegal drugs such as methamphetamine.

Uses

1. PSE is a stimulant and is most commonly used as a nasal or sinus decongestant. It reduces nasal congestion by constricting the blood vessels and reducing swelling in the nasal mucosa. It is often indicated for allergies and common colds associated with nasal congestion.
2. Additional effects include decongestion of the Eustachian tubes and drainage of secretions in the sinus because of its vasoconstriction action.
3. Pseudoephedrine can be used as a topical decongestant or can be orally taken. The benefit of taking the oral form is that it does not cause rebound congestion.
4. Pseudoephedrine may also be used as an antitussive (cough suppression).
5. Because of its sympathomimetic effect, it is also used in priapism (painful and prolonged erection).

Pseudoephedrine Side effects

Pseudoephedrine side effects are sympathomimetic. These include CNS stimulation, excitability, restlessness, insomnia and nervousness, tachycardia or palpitations, tremors and irritability, mania, hypertension, impotence, anginal pain, and rebound congestion.

1. CNS stimulation, excitability, restlessness

Pseudoephedrine releases endogenous norepinephrine which stimulates the sympathetic nervous system to a fight or flight response. This leads to stimulation and excitability. Pseudoephedrine should not be used by a person with an anxiety disorder because it may cause heightened anxiety levels. Other stimulants such as caffeine should be avoided to prevent further pseudoephedrine CNS side-effects.

2. Insomnia and nervousness

Because of heightened stimulation, people taking PSE may experience insomnia and nervousness. These side-effects may be relieved through ingestion of warm milk at bedtime to induce sleeping. Pseudoephedrine should only be taken during the day to prevent difficulty falling asleep at night.

3. Tachycardia or palpitations

Pseudoephedrine causes an adrenergic response.  This means it can increase the stimulation of the heart muscle leading to fast heart rate and/or palpitations. To prevent this, inform your physician if you have a heart condition or wear a pacemaker.

4. Tremors and irritability

Norepinephrine is released in the neuronal synapse which increases nerve impulse transmission in the brain causing elevated motor activities but can be relieved through engaging in activities involving the hand such as using stress balls and range of motion exercises.

5. Mania

People with bipolar disorder may experience mania and restlessness as pseudoephedrine side-effects through over stimulation of the CNS. An anti-manic drug such as valproic acid is often prescribed for manic patients who are advised to avoid further stimulation by remaining in calm and neutral surroundings.

6. Hypertension (high blood pressure)

PSE exerts a vasoconstriction effect. When the arteries are constricted, there is an increase in pressure and peripheral resistance, causing hypertension.  Though this may be treated with antihypertensive medications their effects may be lessened by PSE. Home remedies may include avoidance of high fat and high salt foods. Patients receiving PSE should discuss the presence of hypertension thus allowing their physician to choose an alternative nasal decongestant.

7. Impotence

Penile erection is a major function of the parasympathetic nervous system. In the administration of pseudoephedrine, the sympathetic nervous system is stimulated, thereby relaxing the parasympathetic nervous system, which may eventually lead to impotence. Short-term use of the drug may not cause significant effect on erection, but long-term use may eventually lead to impairment of sexual function.

8. Anginal Pain

Vasoconstriction of the coronary arteries leads to reduced blood flow to the myocardium (heart muscle), increasing its workload. There is a decrease in the oxygen supply to the myocardium which cannot cope with the increase in demand, leading to angina pain or chest pains.

9. Rebound Congestion

As previously stated, pseudoephedrine can be used as a topical decongestant or can be orally taken. The benefit of taking the oral form is that it does not cause rebound congestion.  In other forms, however, rebound congestion may result.
When blood vessels constrict, there is reduction in capillary permeability, which reduces swelling in the nasal passages. This relieves nasal congestion and improves drainage. However, body has a balancing effect to maintain equilibrium, and these blood vessels dilate after constriction to regulate blood pressure and blood circulation. Once the blood vessels dilate, it causes congestion again. The more a person takes a non-oral form of pseudoephedrine, the more the rebound effect will occur. To prevent this, patients should not use PSE for prolonged periods.

Advantages of Pseudoephedrine

Despite the side-effects, it is often prescribed because of its advantages in reducing nasal congestion and as a stimulant. The use of pseudoephedrine is beneficial when proper administration is carried out. The advantage of pseudoephedrine as a nasal decongestant or stimulant is that it has a faster effect than other sympathomimetics. Pseudoephedrine is a powerful medication and is centrally acting, thereby enhancing its effects.
Interactions

1. Pseudoephedrine should not be used concomitantly with MAOI’s (monoamine oxidase inhibitors) because of hypertension.
2. The use of pseudoephedrine with antihypertensive medications reduces their effects on lowering blood pressure.
3. Increase in pacemaker activity may be noted when used concomitantly with digitalis.
4. Kaolin inhibits absorption of pseudoephedrine, while antacids increase the rate of absorption.

Contraindications

Pseudoephedrine is contraindicated in patients with cardiovascular disease, diabetes mellitus, uncontrolled hypertension, prostatic hypertrophy, closed angle glaucoma, coronary artery disease and hyperthyroidism. It is also contraindicated during pregnancy because it causes poor placental perfusion.

News

Pseudoephedrine has been a regulated drug because of its use in the production of methamphetamine by illegal drug makers. It is banned for use by athletes because of its stimulating effect and because it may cause them to test positively for amphetamine use. This has caused its withdrawal from the market.