Before escalating therapy in uncontrolled asthma or COPD, watch the patient use their device. Not ask — watch. Reported adherence and demonstrated technique disagree so often that the question is nearly uninformative, and the commonest reason an inhaler is not working is that the drug is not reaching the lung.
The errors cluster by device type. With a pressurised metered-dose inhaler it is failing to coordinate actuation with inspiration, and breathing in too fast. With a dry powder inhaler it is the opposite — breathing in too slowly to generate the flow the device needs to disaggregate the powder — and exhaling into the mouthpiece, which dumps the dose. Across both it is failing to hold the breath afterwards, and never using a spacer when one is indicated.
Two practical consequences. A patient switched between device types needs retraining, not just a new prescription, because the correct technique is opposite. And an older patient or one with an acute exacerbation may not be able to generate the inspiratory flow a dry powder device requires at all — which is a reason to choose a metered-dose inhaler with a spacer rather than to escalate the drug.
- Ask the patient to demonstrate with their own device at every review where control is inadequate.
- Check inspiratory flow capability before prescribing a dry powder inhaler to an older or frail patient.
- Retrain on switching between device classes — the correct inhalation is fast and deep for one, slow and steady for the other.
- Prescribe and actually supply a spacer with every metered-dose inhaler; it fixes coordination errors outright.
- Count the doses left in the canister — an empty inhaler still actuates and still feels like it is working.
Why it matters
Escalating a drug that is not reaching the lung adds cost and side effects and leaves the actual problem in place.
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