Key Takeaways
- Insulin must be stored in the refrigerator until opened; most can be kept at room temperature for 28-42 days after opening.
- Metformin is first-line therapy for type 2 diabetes; hold before iodinated contrast procedures.
- Levothyroxine should be taken on an empty stomach, 30-60 minutes before breakfast.
- Rescue inhalers (albuterol) work within minutes; maintenance inhalers (ICS) take days to weeks for full effect.
- Many medications require special storage conditions including refrigeration, protection from light, or controlled room temperature.
Last updated: January 2026
Endocrine, Respiratory, CNS, and Storage Requirements
This section covers diabetes medications, thyroid drugs, respiratory medications, CNS agents, and the critical storage requirements every pharmacy technician must know.
Diabetes Medications
Insulin Products
Insulin is classified by onset and duration of action.
| Type | Generic | Brand | Onset | Peak | Duration |
|---|---|---|---|---|---|
| Rapid-Acting | insulin lispro | Humalog | 15-30 min | 0.5-2.5 hr | 3-5 hr |
| Rapid-Acting | insulin aspart | NovoLog | 15-30 min | 1-3 hr | 3-5 hr |
| Rapid-Acting | insulin glulisine | Apidra | 15-30 min | 1-1.5 hr | 3-5 hr |
| Short-Acting | regular insulin | Humulin R, Novolin R | 30-60 min | 2-4 hr | 5-8 hr |
| Intermediate | NPH insulin | Humulin N, Novolin N | 1-2 hr | 4-12 hr | 14-24 hr |
| Long-Acting | insulin glargine | Lantus, Basaglar | 1-2 hr | No peak | 24+ hr |
| Long-Acting | insulin detemir | Levemir | 1-2 hr | No peak | 12-24 hr |
| Ultra-Long | insulin degludec | Tresiba | 1-2 hr | No peak | 42+ hr |
Storage Requirements:
- Unopened: Refrigerate (36-46 degrees F / 2-8 degrees C)
- Opened/In-Use: Room temperature (up to 77-86 degrees F)
- Duration after opening: Varies by product (typically 28-42 days)
- Never freeze insulin
Exam Tip: Cloudy insulins (NPH) must be gently rolled to resuspend; clear insulins should NOT appear cloudy
Oral Diabetes Medications
| Class | Generic | Brand | Key Points |
|---|---|---|---|
| Biguanide | metformin | Glucophage | First-line for T2DM; hold for contrast |
| Sulfonylureas | glipizide | Glucotrol | Risk of hypoglycemia |
| Sulfonylureas | glimepiride | Amaryl | Once daily dosing |
| Sulfonylureas | glyburide | Diabeta | Highest hypoglycemia risk |
| DPP-4 Inhibitors | sitagliptin | Januvia | Weight neutral |
| DPP-4 Inhibitors | linagliptin | Tradjenta | No renal adjustment needed |
| SGLT2 Inhibitors | empagliflozin | Jardiance | CV and renal benefits |
| SGLT2 Inhibitors | canagliflozin | Invokana | Risk of DKA, UTI, yeast infections |
| GLP-1 Agonists | semaglutide | Ozempic (injection), Rybelsus (oral) | Weight loss, once weekly |
| GLP-1 Agonists | liraglutide | Victoza | Weight loss, daily injection |
| GLP-1 Agonists | dulaglutide | Trulicity | Once weekly |
Metformin Counseling:
- Take with food to minimize GI upset
- Hold 48 hours before/after iodinated contrast media
- Rare but serious risk: lactic acidosis
- Do not use in severe kidney disease (eGFR <30)
Thyroid Medications
| Generic Name | Brand Name | Indication | Key Points |
|---|---|---|---|
| levothyroxine | Synthroid, Levoxyl | Hypothyroidism | Take on empty stomach |
| liothyronine | Cytomel | Hypothyroidism | T3, faster acting |
| methimazole | Tapazole | Hyperthyroidism | Blocks thyroid hormone synthesis |
| propylthiouracil (PTU) | n/a | Hyperthyroidism | Used in pregnancy (1st trimester) |
Levothyroxine Administration:
- Take on empty stomach, 30-60 minutes before breakfast
- Separate from calcium, iron, and antacids by 4 hours
- Narrow therapeutic index - brand/generic substitution may affect levels
- Monitor TSH levels regularly
Respiratory Medications
Short-Acting Bronchodilators (Rescue Inhalers)
| Generic Name | Brand Name | Type | Key Points |
|---|---|---|---|
| albuterol | ProAir, Ventolin, Proventil | SABA | Rescue inhaler, works in minutes |
| levalbuterol | Xopenex | SABA | R-isomer of albuterol |
| ipratropium | Atrovent | SAMA | Anticholinergic |
| ipratropium/albuterol | Combivent, DuoNeb | Combination | COPD |
Patient Education: Rescue inhalers are for acute symptoms; using more than 2x/week indicates poor control
Long-Acting Bronchodilators (Maintenance)
| Generic Name | Brand Name | Type | Dosing |
|---|---|---|---|
| tiotropium | Spiriva | LAMA | Once daily |
| formoterol | Foradil | LABA | Twice daily |
| salmeterol | Serevent | LABA | Twice daily |
| umeclidinium/vilanterol | Anoro Ellipta | LAMA/LABA | Once daily |
Black Box Warning (LABAs): Increased risk of asthma-related death when used alone in asthma - always use with ICS
Inhaled Corticosteroids (ICS)
| Generic Name | Brand Name | Key Points |
|---|---|---|
| fluticasone | Flovent | Maintenance therapy |
| budesonide | Pulmicort | Available as nebulizer solution |
| beclomethasone | Qvar | HFA propellant |
| mometasone | Asmanex | Once or twice daily |
ICS Combinations (ICS + LABA):
| Combination | Brand Name | Frequency |
|---|---|---|
| fluticasone/salmeterol | Advair | BID |
| budesonide/formoterol | Symbicort | BID |
| fluticasone/vilanterol | Breo Ellipta | Once daily |
Patient Education:
- Rinse mouth after use to prevent oral thrush (candidiasis)
- Takes days to weeks for full effect - not for acute symptoms
- Do not stop abruptly
CNS Medications
Antidepressants
| Class | Generic Examples | Brand Examples | Key Points |
|---|---|---|---|
| SSRIs | sertraline, fluoxetine, escitalopram | Zoloft, Prozac, Lexapro | First-line for depression/anxiety |
| SNRIs | venlafaxine, duloxetine | Effexor, Cymbalta | Also for nerve pain |
| TCAs | amitriptyline, nortriptyline | Elavil, Pamelor | Anticholinergic effects |
| Atypical | bupropion, mirtazapine | Wellbutrin, Remeron | Bupropion: no sexual side effects |
Black Box Warning (All Antidepressants): Increased suicidal thinking in children, adolescents, and young adults
Benzodiazepines (Schedule IV)
| Generic Name | Brand Name | Onset | Duration |
|---|---|---|---|
| alprazolam | Xanax | Intermediate | Short |
| lorazepam | Ativan | Intermediate | Intermediate |
| diazepam | Valium | Fast | Long |
| clonazepam | Klonopin | Intermediate | Long |
Reversal Agent: Flumazenil (Romazicon)
Sleep Medications
| Generic Name | Brand Name | Schedule | Key Points |
|---|---|---|---|
| zolpidem | Ambien | C-IV | Short-term use; sleep-driving risk |
| eszopiclone | Lunesta | C-IV | May cause metallic taste |
| trazodone | Desyrel | Non-controlled | Off-label for insomnia |
| melatonin | OTC | Non-controlled | Natural hormone; jet lag |
Drug Storage Requirements
Refrigerated Medications (36-46 degrees F / 2-8 degrees C)
| Medication Type | Examples | Notes |
|---|---|---|
| Insulins | All unopened insulin | Room temp 28-42 days after opening |
| Vaccines | Most vaccines | Some require freezer storage |
| Biologics | Humira, Enbrel, Trulicity | Protect from light |
| Eye drops | Latanoprost (Xalatan) | Room temp up to 6 weeks after opening |
| Suppositories | Promethazine, some others | Prevent melting |
| Reconstituted antibiotics | Amoxicillin suspension | Discard after 14 days |
Room Temperature (68-77 degrees F / 20-25 degrees C)
Most medications are stored at controlled room temperature. Excursions between 59-86 degrees F are generally acceptable.
Protect from Light
| Medication | Reason |
|---|---|
| Nitroglycerin | Light degrades the drug |
| Furosemide injection | Photosensitive |
| Metronidazole IV | Photosensitive |
| Nifedipine | Light-sensitive |
Special Storage
| Medication | Requirement |
|---|---|
| Dabigatran (Pradaxa) | Keep in original container; desiccant protects from moisture |
| Nitroglycerin SL tablets | Original glass container; replace every 6 months |
| Epinephrine auto-injectors | Room temperature; check for discoloration |
| Certain chemotherapy drugs | May require freezer or special handling |
Dosage Forms and Routes of Administration
| Route | Abbreviation | Examples |
|---|---|---|
| Oral | PO | Tablets, capsules, liquids |
| Sublingual | SL | Nitroglycerin, ondansetron |
| Buccal | Buccal | Fentanyl buccal tablet |
| Topical | TOP | Creams, ointments, patches |
| Transdermal | TD | Fentanyl patch, nicotine patch |
| Ophthalmic | OU/OD/OS | Eye drops, ointments |
| Otic | AU/AD/AS | Ear drops |
| Nasal | Nasal | Sprays, inhalers |
| Inhalation | INH | MDI, DPI, nebulizer |
| Rectal | PR | Suppositories, enemas |
| Vaginal | PV | Suppositories, creams |
| Subcutaneous | SubQ, SC | Insulin, heparin |
| Intramuscular | IM | Vaccines, testosterone |
| Intravenous | IV | Antibiotics, fluids |
Exam Tip: Know common dosage form abbreviations and which drugs use specific routes
Test Your Knowledge
How should unopened insulin vials be stored?
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D
Test Your Knowledge
A patient using a fluticasone inhaler (Flovent) should be counseled to:
A
B
C
D
Test Your Knowledge
Which medication should be taken on an empty stomach, 30-60 minutes before breakfast, and separated from calcium supplements by 4 hours?
A
B
C
D
Test Your Knowledge
Which type of insulin has NO peak and provides basal coverage for approximately 24 hours?
A
B
C
D
Test Your Knowledge
A patient is prescribed albuterol (ProAir HFA). What type of medication is this, and when should it be used?
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B
C
D