Tiotropium
A long-acting inhaled antimuscarinic used once a day to keep the airways open in COPD, cut flare-ups and help asthma.
Drug card
- How it works
- Blocking airway muscarinic receptors so vagal acetylcholine cannot narrow them
- Used for
- Maintenance treatment of COPD
- Reducing COPD flare-ups
- Add-on maintenance treatment of asthma
- Known for
- Dry mouth
- Its name
- -trop- means an atropine-like antimuscarinic
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does tiotropium work?
A quaternary atropine derivative that binds all five muscarinic subtypes (M1 to M5) with similar affinity; in the airways it works by competitively blocking M3 receptors on smooth muscle and submucosal glands, relaxing the muscle and reducing mucus. Its protection against bronchoconstriction lasts more than 24 hours, and the kidneys clear most of it.
Like other inhaled antimuscarinics: Inhaled antimuscarinics are quaternary relatives of atropine that compete with acetylcholine at muscarinic receptors, mainly M3, on airway smooth muscle and mucus glands. Acetylcholine released by the vagus nerve can then no longer tighten the airways or drive mucus secretion, so the airways widen. Their effect is mainly local in the lungs; ipratropium is short-acting and tiotropium lasts a full day.
Uses
What is tiotropium used for?
- Maintenance treatment of COPD
- Reducing COPD flare-ups
- Add-on maintenance treatment of asthma
Side effects
Side effects of tiotropium
- Dry mouthKnown for
- Constipation, rarely bowel obstruction (ileus)
- Indigestion
- Urinary tract infection
- Difficulty passing urine (urinary retention)Serious
- Narrow-angle glaucoma, blurred vision, eye painSerious
- Palpitations and fast heartbeat
- Paradoxical bronchospasmSerious
- Allergic reactions, including angioedemaSerious
- Oral thrush
- Hoarse voice
- Nosebleeds
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- A maintenance drug only: it does not relieve an acute attack.
- Narrow-angle glaucoma and bladder-outflow obstruction can worsen.
- In moderate to severe kidney impairment levels rise, so anticholinergic effects are watched closely.
- Care with severe milk-protein allergy (powder) or atropine allergy; other anticholinergics add to its effects.
Good to know: Its effect outlasts 24 hours, so unlike ipratropium it is used once a day; breathing usually starts to ease after 3 to 7 days of regular use.
Remember it
A way to remember it
Block the vagus, open the airways.
The vagus nerve narrows the airways through acetylcholine at muscarinic receptors; these drugs block that signal, and like atropine they can dry the mouth and, rarely, raise eye pressure or hold back urine.
Written for biofideX
Its name
-trop- means atropine-like antimuscarinic
Marks atropine relatives. Ipratropium and tiotropium add -ium: as quaternary ammonium compounds they are barely absorbed and act in the airways. Somatropin, a growth hormone, fits by chance.
- Every drug name stem
Its class
Inhaled antimuscarinics
Other inhaled antimuscarinics with a card:
Easily mixed up with antimuscarinics, short-acting beta-2 agonists and long-acting beta-2 agonists.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Tiotropium bromide inhalation powder: label (DailyMed)
- Tiotropium bromide (NCI Thesaurus)
- Tiotropium inhalers (NHS)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Lungs and allergy
Tiotropium is one of 16 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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