Inhalers Day Supply Calculations (MDI, DPI, Nebulizer Solution)
Table of Contents
Inhalers and Day Supply Calculation
Calculating the day supply of an inhaler is essential for proper medication management, insurance billing, and ensuring patients have enough medication.
The day supply depends on the total number of doses in the inhaler and the prescribed dosage (how many puffs per day).
The day supply depends on the total number of doses in the inhaler and the prescribed dosage (how many puffs per day).
1. Know the Inhaler Type
- Metered Dose Inhalers (MDIs): Deliver a fixed number of puffs (e.g., 120 actuations).
- Dry Powder Inhalers (DPIs): Also contain a set number of doses (e.g., 60 blister packs).
- Respimat inhalers: Contain a set number of actuations (e.g., 120 sprays).
- Nebulizer solutions: Measured in mL or unit doses, not “puffs”.
2. Find the Total Number of Doses
Look at the packaging or drug database. It will say something like:- 200 inhalations
- 60 doses
- 120 metered sprays
3. Confirm Prescribed Usage
Check the prescription for dosing frequency, such as:- 2 puffs every 4 to 6 hours PRN
- 1 puff twice daily
- 2 puffs QID
4. Calculate Day Supply
Inhalers and Day Supply Calculation Formula
What are Metered Dose Inhalers (MDIs)?
Metered Dose Inhalers (MDIs) are handheld devices that deliver a specific amount of medication in aerosol form directly into the lungs. They use a propellant to release the drug when the canister is pressed.MDIs are commonly used to treat asthma, COPD, and other respiratory conditions. Proper technique, including slow, deep inhalation and coordination between actuation and breathing, is essential for effective drug delivery.
Spacers are often recommended to improve medication deposition and reduce side effects like oral thrush when using corticosteroids.
Common Metered Dose Inhalers (MDI)
| Brand Name | Generic Name | Total Puffs |
| ProAir HFA | Albuterol | 200 |
| Proventil HFA | Albuterol | 200 |
| Ventolin HFA | Albuterol | 200 |
| Airsupra | Albuterol / Budesonide | 120 |
| QVAR RediHaler | Beclomethasone | 120 |
| Breyna | Budesonide / Formoterol | 120 |
| Symbicort | Budesonide / Formoterol | 120 |
| Alvesco | Ciclesonide | 60 |
| Flovent HFA | Fluticasone propionate | 120 |
| Advair HFA | Fluticasone / Salmeterol | 120 |
| Bevespi Aerosphere | Glycopyrrolate / Formoterol | 120 |
| Atrovent HFA | Ipratropium | 200 |
| Combivent Respimat | Ipratropium / Albuterol | 120 |
| Xopenex HFA | Levalbuterol | 200 |
| Asmanex HFA | Mometasone | 100 |
| Dulera | Mometasone / Formoterol | 120 |
| Spiriva Respimat | Tiotropium | 60 |
| Stiolto Respimat | Tiotropium / Olodaterol | 60 |
What are Dry Powder Inhalers (DPIs)?
Dry Powder Inhalers (DPIs) are handheld devices that deliver medication in the form of a dry powder directly to the lungs. Unlike metered-dose inhalers (MDIs), DPIs are breath-actuated, meaning the patient’s inhalation provides the force to disperse and inhale the medication—no propellant is used.DPIs are commonly used for asthma and COPD treatments. Proper inhalation technique is crucial: a quick, deep breath ensures effective drug delivery. DPIs come in various designs like Diskus, Ellipta, and HandiHaler, each with unique loading and usage methods. They are ideal for patients who may struggle with MDI coordination.
Common Dry Powder Inhalers (DPI)
| Brand Name | Generic Name | Total Doses |
| ProAir Digihaler | Albuterol | 200 |
| Pulmicort Flexhaler | Budesonide | 60 / 120 |
| Arnuity Ellipta | Fluticasone furoate | 30 |
| ArmonAir Digihaler | Fluticasone propionate | 60 |
| Flovent Diskus | Fluticasone propionate | 60 |
| Advair Diskus | Fluticasone / Salmeterol | 60 |
| AirDuo RespiClick | Fluticasone / Salmeterol | 60 |
| Wixela Inhub | Fluticasone / Salmeterol | 60 |
| AirDuo Digihaler | Fluticasone / Salmeterol | 60 |
| Trelegy Ellipta | Fluticasone / Umeclidinium / Vilanterol | 30 |
| Breo Ellipta | Fluticasone / Vilanterol | 30 |
| Seebri Neohaler | Glycopyrrolate | 30 |
| Arcapta Neohaler | Indacaterol | 30 |
| Utibron Neohaler | Indacaterol / Glycopyrrolate | 30 |
| Asmanex Twisthaler | Mometasone | 30 / 60 / 120 |
| Serevent Diskus | Salmeterol | 60 |
| Spiriva HandiHaler | Tiotropium | 30 |
| Incruse Ellipta | Umeclidinium | 30 |
| Anoro Ellipta | Umeclidinium / Vilanterol | 30 |
What are Respimat Inhalers?
Respimat inhalers are a type of Soft Mist Inhaler (SMI) that deliver medication as a slow-moving mist, providing better drug deposition in the lungs compared to traditional metered-dose inhalers (MDIs).Unlike MDIs, Respimats do not require a propellant and are breath-actuated. They are primarily used for conditions like asthma and COPD, delivering medications such as LAMA, LABA, or a combination. Due to their gentle mist, Respimats are often preferred for patients with difficulty coordinating an MDI. Popular brands include Spiriva Respimat, Combivent Respimat, and Stiolto Respimat.
Common Respimat Inhalers
| Brand Name | Generic Name | Total Puffs |
| Combivent Respimat | Ipratropium / Albuterol | 120 |
| Striverdi Respimat | Olodaterol | 60 |
| Spiriva Respimat | Tiotropium | 60 |
| Spiriva Respimat (asthma) | Tiotropium | 60 |
| Stiolto Respimat | Tiotropium / Olodaterol | 60 |
What are Nebulizer Solutions/Vials?
Nebulizer solutions/vials are liquid medications used in nebulizers to treat respiratory conditions like asthma and COPD. They deliver the medication as a fine mist that patients inhale through a mask or mouthpiece.These solutions can include bronchodilators, corticosteroids, or antibiotics and are typically dosed multiple times daily.
Common Nebulizer Solutions/Vials
| Brand Name | Generic Name | Size of Each Vial |
| Albuterol Sulfate | Albuterol | 2.5 mg/3 mL |
| Proventil Nebulizer | Albuterol | 2.5 mg/3 mL |
| Ventolin Nebulizer | Albuterol | 2.5 mg/3 mL |
| Brovana | Arformoterol | 15 mcg/2 mL |
| Pulmicort | Budesonide | 0.25 mg/2 mL, 0.5 mg/2 mL |
| Perforomist | Formoterol Fumarate | 20 mcg/2 mL |
| Arcapta Neohaler | Indacaterol | 1.75 mg/2 mL |
| Atrovent | Ipratropium Bromide | 0.02% (0.5 mg/2.5 mL) |
| Combivent Respimat | Ipratropium / Albuterol | 0.5 mg/2.5 mL |
| Duoneb | Ipratropium / Albuterol | 0.5 mg/2.5 mL |
| Xopenex | Levalbuterol | 0.63 mg/3 mL or 1.25 mg/3 mL |
| Tobi | Tobramycin | 300 mg/5 mL |
Metered Dose Inhaler (MDI) Practice Questions
Question 1: A patient is prescribed Ventolin HFA (Albuterol) 2 puffs every 4-6 hours as needed. The inhaler contains 200 puffs. What is the maximum day supply?
Explanation:- Max puffs per day = 2 puffs × 6 times = 12 puffs/day.
- Day supply = 200 puffs ÷ 12 puffs/day = 16 days.
Question 2: A patient is prescribed Flovent HFA (Fluticasone propionate) 2 puffs twice daily. The inhaler contains 120 puffs. The day supply of this inhaler is __________ days.
Explanation:- Max puffs per day: 2 puffs × 2 times/day = 4 puffs/day.
- Day supply = 120 puffs ÷ 4 puffs/day = 30 days.
Question 3: Xopenex HFA (Levalbuterol) contains 200 puffs. A patient is prescribed 2 puffs every 4-6 hours, with a maximum day supply?
Explanation:- Max puffs per day = 2 puffs × 12 doses = 24 puffs/day.
- Day supply = 200 puffs ÷ 24 puffs/day = 8.33 days.
- Round to 8 days.
Question 4: A patient is prescribed Alvesco (Ciclesonide) 1 puff daily. The inhaler contains 120 puffs. How many days will the inhaler last?
Explanation:- Max puffs per day: 1 puff/day = 1 puff daily.
- Day supply = 120 puffs ÷ 1 puff/day = 120 days.
Powdered Dose Inhaler (PDI) Practice Questions
Question 5: A patient is prescribed Flovent Diskus (Fluticasone propionate) 250 mcg twice daily (1 puff in the morning and 1 in the evening). The inhaler contains 60 doses. How many days will this inhaler last?
Explanation:- Since the prescribed dose is 2 puffs daily (1 puff in the morning and 1 in the evening), and
- Inhaler contains 60 doses, the
- Day supply is: 60 doses ÷ 2 puffs/day = 30 days.
Question 6: A patient is prescribed Symbicort (Budesonide/Formoterol) inhaler with 120 doses. If the patient uses 2 puffs twice daily, the inhaler will last for ______ days.
Explanation:- The patient is using 4 puffs per day (2 puffs AM, 2 puffs PM). Day supply is: 120 doses ÷ 4 puffs/day = 30 days.
Question 7: An inhaler of Pulmicort Flexhaler (Budesonide) contains 120 doses. The prescription is for 1 puff twice daily. How many days will this inhaler last, and what is the total number of puffs used per month?
Explanation:- 1 Puff twice daily = 2 puffs / day
- Days supply: 120 doses ÷ 2 puffs / day = 60 days Total puffs per month: 2 puffs/day × 30 days = 60 puffs per month
Question 8: A patient is prescribed Arnuity Ellipta (Fluticasone furoate) with 30 doses. The patient is directed to use 1 puff daily. After 10 days of use, the patient reports they have used 5 doses. How many doses remain, and how many days of treatment are left?
Explanation:- Doses remaining: 30 doses – 5 doses used = 25 doses remaining
- Days remaining: 25 doses ÷ 1 puff/day = 25 days remaining
Respimat Inhaler Practice Questions
Question 9: A patient is prescribed Spiriva Respimat for asthma with the following directions: “2 puffs once daily.” The Spiriva Respimat inhaler contains 60 puffs. What is the day supply of this inhaler?
Explanation:- Total puffs: Each Spiriva Respimat inhaler has 60 puffs.
- Dose prescribed: 2 puffs once daily
- Total day supply: 60 puffs ÷ 2 puffs/day = 30 days.
Question 10: A patient is prescribed Combivent Respimat with the following directions: “1 puff QID” (four times a day). The inhaler contains 120 puffs. If the patient forgets to take a dose for 2 days, how many days will the inhaler last?
Explanation: This question has 2 parts- Part 1: The patient typically uses 1 puff four times a day, so the inhaler would (120 puffs ÷ 4 puffs/day) = last 30 days.
- Part 2: If they miss 2 days, they still have 2 extra days left from the missed doses. Therefore, the inhaler will last 32 days.
Nebulizer Solutions/Vials Practice Questions
Question 11: A patient is prescribed Albuterol 2.5 mg/3 mL nebulizer solution to be used QID (4 times a day). The package size is 90 mL. How many days will the package last?
Explanation:- Determine the volume used per day:
- The prescribed dose is 3 mL QID (4 times a day).
- So, the patient uses 3 mL × 4 doses = 12 mL/day.
- Calculate the day supply:
- The total volume in the package is 90 mL.
- To calculate how many days the package will last:
Answer: The package will last 7.5 days.
Question 12: A patient is prescribed Budesonide (Pulmicort) 0.5 mg/2 mL nebulizer suspension to be used BID (twice daily). The package contains 30 vials, each with 2 mL. How many days will the package last?
Explanation:- Determine how many vials are used per day:
- The dose is 1 vial (2 mL) BID.
- So, the patient uses 2 vials per day.
- Calculate the day supply:
- The package contains 30 vials.
Answer: The package will last 15 days.
