College of Pharmacy & Nutrition
University of Saskatchewan
110 Science Place
Saskatoon SK S7N 5C9

DRUG SHORTAGES

Drug shortages can occur for a variety of reasons.The factors currently affecting drug supply are shortages of raw materials, quality control issues which led to voluntary withdrawal and longer production times for some products and competition among drug manufacturers. The problem is expected to ease somewhat with renewed production in some cases and takeover of supply by another company in others. For more details see the environmental scan on Drug Supply Disruptions recently posted on the CADTH website.

In the meantime, pharmacists are responsible for ensuring patients continue to receive appropriate drug therapy. A general protocol to follow in handling drug shortages is offered below:

  1. Ensure there is a valid indication for the drug. Review the patient’s drug and medical history. For a checklist of criteria to consider, check the CPhA Drug Shortages Guide pg 4 - 6.
  2. Substitution of a different brand of the same drug (molecule):
    • Check the Saskatchewan Prescription Drug Plan (SPDP) Formulary for interchangeable brands of the same drug; then check for availability of these brands. (Call wholesalers, manufacturers)
    • If none are available, is there a non-interchangeable brand of the same drug.in the same dosage form? Obtain authorization for substitution from doctor, start at same dose or a reduced dose and titrate to desired effect (especially important if drug has a narrow therapeutic index) and monitor for beneficial and adverse effects. Follow-up with the patient in 24 – 48 hours, as indicated by kinetic and pharmacologic characteristics of the drug.
    • If no Formulary drug in the same dosage form is available, check Health Canada Drug Product Database for other brands that may be available and proceed as above.
    • If none available, is there a different dosage form of the same drug? Obtain authorization for substitution from doctor, start at appropriate dose and titrate to desired effect (especially if narrow therapeutic index) and monitor for beneficial and adverse effects. Follow-up with the patient in 24 – 48 hours as indicated by kinetic and pharmacologic characteristics of the drug.
    • If no Formulary drug is available, check Drug Product Database for other dosage forms that may be available and proceed as above.
    • As necessary, consult SPDP regarding coverage for substituted brand.
  3. If no other forms of the same molecule are available, substitution of another drug in the same therapeutic class can be considered. Check the references below for dose equivalence data. This information is not always available. Even when a therapeutically equivalent dose is administered, patients may react differently. Pharmacists should follow-up with the patient frequently until the patient is stabilized on the new medication.
    • Rx Files Charts - www.rxfiles.ca
    • e-therapeutics + (available at SHIRP)
    • Handbook of Clinical Drug Data , 2010, 11th edition - hardcopy text
  4. If there is not a therapeutic equivalent, check treatment guidelines and recommend a drug from another pharmacologic class. Monitor and titrate to desired effect.
  5. Compounding capsules or tablets in the desired doses when other strengths of drug are available or from bulk powders may be another option, especially in instances where there is not a readily available or acceptable substitute.

INFORMATION ON SPECIFIC DRUGS


Drug Comments
 
Allopurinol (Zyloprim)

Zyloprim currently available.

Discontinuation in patients with mild gout and no attacks for years may be considered.

Alternatives:
Xanthine oxidase inhibior: febuxostat (Uloric) 80 mg PO once daily. (new, $$)
2nd line prophylaxis:
Colchicine 0.6 - 1 mg PO once daily; reduce dose in elderly, renal impairment
Uricosuric agents: ineffective if CrCl <50 ml/min; not in urate over-producers; not if history of nephrolithiasis; liberal fluid intake required:
- Probenecid: inital dose 250 mg PO BID, titrate to 0.5 - 2 g / day in two to three divided doses
- Sulfinpyrazone: inital 100-200 mg PO BID, increase dose to 200 - 400 mg PO BID

Acetazolamide AA Pharma brand available

Alternatives:
Glaucoma – methazolamide
Altitude sickness - dexamethasone
Amitriptyline One brand available - Elavil FCT by AAPharma - all strengths

Alternatives:
Nortriptyline (convert at roughly ½ the dose of amitriptyline and titrate as needed), Imipramine (convert at same dose as amitriptyline); beta-blockers (migraine prophylaxis); SSRIs, SNRIs
Beclomethasone nasal spray
Budesonide nasal spray
Flunisolide nasal spray (Rhinalar)

Apo- and Mylan-beclomethasone now available
Mylan- budesonide 64 ug, 100 ug now available
Apo-flunisolide 0.025 % biw available

Alternatives:
Fluticasone
Ciclesonide (Omnaris)
Betahistine (Serc) Currently available - brand name and generic.

Alternatives:
Compounding pharmacies may be able to make capsules for patients

Carbamazepine

 Available in all strengths and quantities
Cefaclor Ceclor capsules available; liquid unavailable

Alternatives:
trimethoprim-sulfamethoxazole; fluoroquinolones
Cephalexin

All formulations and strengths available

Alternatives:
Cellulitis: cloxacillin
UTIs: TMP/SMX, nitrofurantoin, fluoroquinolone
Skin infections: cloxacillin, clarithromycin, azithromycin, clindamycin, cefadroxil
Chlorthalidone

Currently available.

Alternatives:
If also on atenolol and strengths match, can go to the combination product (Tenoretic, generics)
Hydrochlorothiazide at equivalent dose for hypertension or edema
Clavulin

All strengths available except the 250mg/62.5 oral suspension

Alternatives:
macrolides, clindamycin (but not if need Gram neg coverage), fluroquinolones, cefixime, cefuroxime
Cotrimoxazole

All brands of oral suspension are being shorted.

Options: Crush tablets, compound oral suspension

Alternatives: Another antibiotic with similar spectrum of activity
Desipramine

All strengths are available

Alternatives:
Nortriptyline and desipramine are both secondary amine TCAs and generally better tolerated than tertiary amine TCA's (convert to nortripytline at roughly ½ the dose of desipramine and titrate as needed), Imipramine, amitriptyline, clomipramine (convert at same dose as desipramine); beta-blockers (migraine prophylaxis); SSRIs, SNRIs
Diazepam

All strengths are currently available.

Alternatives for 2 mg:
Use ½ x 5mg tablet short term; 0.5mg lorazepam approximately equivalent to 2.5 mg diazepam (may require shorter dosing interval due to shorter half-life compared to diazepam)
Diltiazem ER 180mg, 240mg and 360mg

Diltiazem CD and Tiazac XC are available in all strengths. Certain generic brands are unavailable.

Alternatives:
Same daily dose of alternative dilitazem formulations
Hypertension: verapamil, amlodipine, felodipine and nifedipine XL
S table angina: amlodipine, nifedipine, and verapamil IR are indicated. IR diltiazem and IR nifedipine not recommended for monotherapy.

Ethosuximide

Zarontin 250 mg capsules unavailable

Options: Zarontin 50 mg/ml syringe available

Alternatives: switch to another anticonvulsant- monitor for tolerability and seizure control
Fluconazole

Apo- fluconazole 150 mg now available

150mg single dose capsule available OTC as Canesoral without Rx

Folic Acid

Euro-folic 5 mg tablets in 1000's is in stock. 5 mg tablets packaged in 100's are not available
Fosfomycin

Fosfomycin currently not available in Canada and future availability unknown.

It is a one-dose oral antibiotic indicated only for uncomplicated UTI in females. There are no other one-dose oral antibiotics for UTI currently available.

Gentamicin ophth/otic

Ophthalmic drops/ ointment and otic drops are available

Alternatives:
SPDP covers Optimyxin, Polytrim, PMS-Polytrimethoprim
Polysporin available OTC
Gliclazide MR

Diamicron MR 30 mg and 60 mg available; Gliclazide MR 30 mg (AA Pharma Inc) available

Alternatives:
Gliclazide 80 mg immediate release (various brands) - to substitute for MR, start with 80 mg IR per 30 mg MR. Doses higher than 80 mg daily should be divided BID. Dose should be adjusted based on blood glucose monitoring after switch.
Hepatitis B vaccine Engerix B adult and pediatric now available; Recombivax Thiomersol Free also available

No alternatives available
Hydroxyzine All strengths of Apo-hydroxyzine available Jan. 10th/2012; All strengths of Teva-hydroxyzine are back-ordered until Apr. 15/2012
Iron Dextran Infufer 50 mg/ml out of stock indefinitely; Dexiron 50 mg/ml will be avilable Jan. 15/2012
Isosorbide Dinitrate

AA Pharma has taken over marketing from Apotex. Now available.

Alternatives:
isosorbide mononitrate, nitroglycerin
Linessa (ethyinyl estradiol 25mcg/desogestrel 100/125/150 mcg) Available Jan 15, 2012.
Medroxyprogesterone acetate

All strengths currently available. MPA powder is available.

Options: Compound capsules from bulk powder

Alternatives: micronized progesterone, norethindrone acetate, megestrol acetate, estradiol/progestin combinations
(See PDF for detailed information.)
Methotrimeprazine (Nozinan & generics)

All strengths now available

Alternatives:
Chlorpromazine, haloperidol (note do not have analgesic effects)
Penicillin V

Tablets currently available in all strengths. Suspensions and injections are being shorted

Alternatives:
Strep throat : amoxicillin, erythromycin (if penicillin allergic)
Pentoxifylline

Currently available.

Alternatives: aspirin, clopidogrel, dipyridamole, ticlopidine
Primidone

AA Pharma 125 mg and 250 mg tablets now available
Phenytoin

Dilantin® 100 mg and 30 mg extended release capsules shorted off and on in Saskatchewan.
Pfizer has been trying to ship out about every two weeks with what is available.

Alternatives: Infatabs, oral suspension, injectable.
Important - see PDF for instructions on switching.
Pizotifen (Sandomigran) 0.5mg tablets unavailable indefinitely

Sandomigran DS (1 mg) is still available.

Prochlorperazine (Stemetil & generics) Currently available.

Alternatives:
Antinauseant: metoclopramide, chlorpromazine
Spironolactone

Currently available

Capsules can be compounded from bulk powder

Alternatives:
Aldactazide, Novo-spirozine if patient is also taking hydrchlorothiazide
Amiloride, triamterene, eplenerone depending on indication
Terconazole (Terazol 3 ovules or duopack) 7 day cream (0.4%) and Duopak are now available

Alternatives: various brand name and generic vaginal antifungals are available OTC; single-dose oral fluconazole 150mg is now available OTC;
SPDP reimburses Canesten (clotrimazole) creams and ovules and single-dose fluconazole 150mg (Fluconazole may be in short supply)

Testosterone
Testosterone enanthate 200 mg/ml
(Delatestryl)
Testosterone cypionate 100 mg/ml (Pfizer, Sandoz)

Not currently available.
Expected availability date for testosterone cypionate - week of Feb. 20, 2012
Expected availability date for Delatestryl is April 2012

Option: Testosterone enanthate and testosterone cypionate (100 mg/ml) can be substituted at same mg/dose and same frequency (Note different concentrations of testosterone cypionate products and Delatestryl - e.g. a patient receving 0.5 ml (100 mg) Delatestyl would require 1 ml (100 mg) of testosterone cypionate.)

Alternatives: Oral or topical formulations of testosterone (See PDF)
Tetracycline

 Apo- / AA Pharma Inc 250 capsules available
Verapamil

Isoptin SR, Mylan-verapamil SR available
Alternatives:
Immediate release at same daily dose (or as close as possible)
Hypertension: amlodipine, diltiazem (CD, Tiazac reg, Tiazac XC), felodipine , nifedipine (XL)
Stable angina: amlodipine, diltiazem and nifedipine XL are indicated. IR diltiazem and IR nifedipine not recommended for monotherapy.
Zostavax Supply of Zostavax is currently limited - check www.zostavax.ca - some doses may still be available in certain areas.

No alternatives available

Adapted with permission from chart compiled by: Kelly Crotty, BScPhm, Desjardins Pharmacy, Cynthia Way, BScPhm, The Ottawa Hospital and Barry Power, PharmD, Rideau Family Health Team and L’Équipe de santé familiale communautaire de l'Est d'Ottawa