[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Nasal decongestants](https://durgical.com/en/pharmacology/classes/nasal-decongestants/) › Pseudoephedrine

# Pseudoephedrine

## Nasal decongestants?

Nasal decongestants

An oral decongestant that shrinks nasal vessels; it can raise blood pressure and heart rate and must never be taken with MAO inhibitors.

Updated Nov 1, 2026

## Quick facts

**Group**
[Nasal decongestants](https://durgical.com/en/pharmacology/classes/nasal-decongestants/)

**Target**
Noradrenaline release from sympathetic nerve endings (indirect), with some direct alpha action

**Used for**
Nasal congestion of colds

**Key effects**
Nervousness · Difficulty sleeping

**Monitor**
Blood pressure and heart rate · Sleep and nervousness

**ATC**
R01BA02

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

Pseudoephedrine is a stereoisomer of ephedrine. It acts mostly indirectly: it is taken up into sympathetic nerve endings and displaces noradrenaline, which then stimulates alpha-adrenergic receptors in the nasal mucosa and constricts its swollen vessels. Because it acts throughout the body, it also raises blood pressure and heart rate, stimulates the brain (insomnia, nervousness) and tightens the bladder neck.

- Pseudoephedrine enters sympathetic nerve endings
- It releases noradrenaline onto alpha receptors
- Nasal vessels constrict and the swelling falls
- The same effect elsewhere raises blood pressure

## Indications

- Nasal congestion of colds [Common cold (acute viral rhinopharyngitis) →](https://durgical.com/en/conditions/common-cold/)
- Nasal congestion of allergic rhinitis, usually with an antihistamine [Allergic rhinitis →](https://durgical.com/en/conditions/allergic-rhinitis/)
- Sinus congestion and pressure [Acute rhinosinusitis →](https://durgical.com/en/conditions/acute-rhinosinusitis/)

## Adverse effects

### Common

- Nervousness, restlessness and dizziness
- Difficulty sleeping
- Fast heartbeat and palpitations
- Raised blood pressure

### Serious (rare, important)

- Hypertensive crisis with MAO inhibitors
- Arrhythmia or myocardial ischaemia in susceptible patients
- Urinary retention with prostate enlargement
- Serious effects or death in young children

## Contraindications

- Taking an MAO inhibitor or within two weeks of stopping one
- Children under 4 years with non-prescription products
- Caution in hypertension, heart disease, diabetes, hyperthyroidism, glaucoma and prostate enlargement

## Key interactions

**MAO inhibitors**
Hypertensive crisis

**Other sympathomimetics and stimulants**
Additive rise in blood pressure and heart rate

**Antihypertensives, including beta-blockers**
Reduces their blood-pressure-lowering effect

**Theophylline**
Additive stimulant effects

## What is monitored

- Blood pressure and heart rate in patients with cardiovascular disease
- Sleep and nervousness
- Urination in older men

## Administration and safety

- Oral tablets or liquid; extended-release tablets are swallowed whole
- The last dose of the day is taken several hours before bedtime
- Sale is restricted in many countries because it can be made into methamphetamine

## Pregnancy and breastfeeding

Oral decongestants are generally avoided in pregnancy, especially in the first trimester; the clinician decides.

## Nursing care

- Check blood pressure before use in patients with hypertension or heart disease
- Ask about MAO inhibitors and stimulants
- Teach to stop and seek advice if symptoms last more than a week or come with fever

## Pharmacokinetics

**Absorption**
Well absorbed by mouth; immediate- and extended-release forms

**Metabolism**
Little metabolism

**Elimination**
Mostly unchanged in the urine; faster in acidic urine

**Onset and duration**
Within about half an hour

## Memory aid

PSEUDOephedrine: Pressure Spikes, Eyes open at night (insomnia), Urine stops, Don't mix with MAOIs.

## Test yourself

Think of the answer, then tap the question to see it.

## Does pseudoephedrine act mainly directly or indirectly on adrenergic receptors?

Mainly indirectly, by releasing noradrenaline from sympathetic nerve endings.

## Which drug class makes pseudoephedrine dangerous, and what happens?

MAO inhibitors; hypertensive crisis.

## Why is pseudoephedrine a problem in an older man with an enlarged prostate?

Alpha stimulation tightens the bladder neck and can cause urinary retention.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/pseudoephedrine/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 3

- [Oxymetazoline](https://durgical.com/en/pharmacology/oxymetazoline/)
- [Xylometazoline](https://durgical.com/en/pharmacology/xylometazoline/)
- [Loratadine](https://durgical.com/en/pharmacology/loratadine/)

## Related conditions 3

- [Common cold (acute viral rhinopharyngitis)](https://durgical.com/en/conditions/common-cold/)
- [Allergic rhinitis](https://durgical.com/en/conditions/allergic-rhinitis/)
- [Acute rhinosinusitis](https://durgical.com/en/conditions/acute-rhinosinusitis/)

[← Back to the class: Nasal decongestants](https://durgical.com/en/pharmacology/classes/nasal-decongestants/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [Pseudoephedrine: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a682619.html) (MedlinePlus (U.S. National Library of Medicine), 2025); [Decongestants - NHS](https://www.nhs.uk/medicines/decongestants/) (NHS, 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=R01BA02) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/pseudoephedrine/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/pseudoephedrine/
