Which of the following are the advantages of Dry Powder Inhalers (DPIs) over Metered Dose Inhalers (MDIs)?
1. It requires less manual dexterity
2. It does not require spacer
3. It is effective in patients with low FEV₁ (< 1 L)
4. There is no need to coordinate device puffs with inhalation
Select the correct answer using the code given below:

Correct option is B

Ans. (b) Sol. Dry Powder Inhalers (DPIs) have several advantages over Metered Dose Inhalers (MDIs):
· Requires less manual dexterity (1): DPIs do not require the same level of coordination or precision that MDIs do, making them easier for patients with limited dexterity.
· Does not require spacer (2): Unlike MDIs, DPIs do not require a spacer to ensure proper medication delivery, making them more user-friendly.
· Effective in patients with low FEV₁ (< 1 L) (3): DPIs are effective even in patients with low Forced Expiratory Volume in 1 second (FEV₁), as they deliver the medication by the patient’s own inhalation effort.
· No need to coordinate device puffs with inhalation (4): This is actually not an advantage of DPIs. Unlike MDIs, where the inhaler must be activated at the same time as the patient inhales, DPIs rely on the patient’s inhalation to trigger the release of medication.
Explanation of each option:
· (a) 1 and 2 only – Incorrect. While DPIs do not require a spacer and need less manual dexterity, they are not more effective in patients with low FEV₁, so option 3 is excluded.
· (b) 1, 2 and 3 – Correct. DPIs require less dexterity, do not require a spacer, and are effective in patients with low FEV₁, making this the most accurate answer.
· (c) 1, 2 and 4 – Incorrect. Although DPIs do not require a spacer and are easier to use, they still need coordination between inhalation and activation, so option 4 is incorrect.
· (d) 2 and 3 only – Incorrect. While DPIs do not require a spacer and are effective in low FEV₁ patients, they also require less manual dexterity, which is not addressed in this option.