Externship Projects

To look up

2006-09-17T14:36:00.000-07:00

Strange things that I have seen doctors do that I'd like to look up:
gabapentin prn
super high erythromycin dose by dermatologist

Clozapine registries

2006-09-15T22:30:00.000-07:00

This is a comprehensive list of the companies marketing clozapine as of September 2006:

Novartis has brand name Clozaril registry at www.clozaril.com
Par has www.parclozapine.com
Mylan has CPAS at www.mylan-clozapine.com
Ivax has www.clozapine-registry.com (previously marketed by Zenith-Goldline Pharmaceuticals)
Caraco is at www.caracoclozapine.com

FazaClo is the ODT version www.fazaclo.com

Data from FDA Orange Book and Google Searches (gotta love them)

Article on Plan B

2005-12-12T10:23:00.000-08:00

From "60 Minutes", an article on Plan B.

Opioid Dose Conversions-focus on methadone

2005-12-06T12:57:00.000-08:00

Resources:

Global RPh- has an automated narcotic conversion calculator. The only tricky part is the "Reduction for incomplete cross tolerance" field. This is a calculation that takes into consideration the concept of starting with a less than equianalgesic dose to avoid overdosing the patient. Many clinicians start with a 25-50% dose reduction.

American Family Physician article on using methadone for chronic pain treatment. A concise article with easy-to-use dosing tables.

OHSU opioid management document-has some dose conversion charts, but is harder to use. This does not include information on methadone dosing.

DOSE CONVERSIONS:
CAUTION: methadone conversions are non-linear. Again, the American Family Physician article gives a good example of this. (One way to think of this non-linear pattern is to think that morphine and other opioids "top out" more easily than methadone, while methadone keeps its potency at very high doses.)

Morphine:Methadone conversion ratio for-
under 100 mg morphine 3:1 , or, 33% of morphine dose
100-300mg morphine 5:1 , or, 20% of morphine dose
300-600 mg morphine 10:1 , or, 10% of morphine dose
600-800 mg morphine 12:1 , or, 8.3% of morphine dose
800-1000 mg morphine 15:1 , or, 6.7% of morphine dose
over 1000 mg morphine 20:1 , or, 5% of morphine dose.

Equianalgesic doses of other opioids:
30 mg morphine = 30 mg hydrocodone = 7.5 mg hydromorphone = 20 mg oxycodone

TO CALCULATE: add up the total daily dose of opioid, convert it to morphine equivalents, and multiply it by the % in the table above. Reduce this about 25% to get a starting dose. Divide this into 3 daily doses, to be taken every 8 hours.

EXAMPLE #1: Conversion of Vicodin to methadone: Your patient is taking 2 vicodin (5/500) four times daily for a total of 40 mg hydrocodone per 24 hours.
The equianalgesic dose of methadone is 13.2 mg (=40 x 0.33). You decide to start at about 75% of that dose, or 10 mg methadone/24 hours.
The usual starting dose schedule is q 8 hours, and methadone comes as 5 mg, 10 mg, and 40 mg tablets. 10 mg is not conveniently divided among three doses.

Your patient has the highest pain level in the late afternoon, so you decide to dose 2.5 mg q am (about 7 am for this patient), 5 mg at about 3 pm, and 2.5 mg q hs.
You counsel the patient to not expect the full level of pain relief from methadone during the first week, and they may need vicodin for breakthrough pain during this time. You schedule a follow-up in 1 week.

TO MONITOR: Pain levels (pain diary can help), sedation, constipation.

Methadone drug interactions:
Partial opiate agonists: these knock the methadone off of the receptors and can precipitate withdrawl symptoms.
CYP 3A4 inhibitors can increase the systemic methadone levels.

Documented drug interactions (not a comprehensive list):
Increase methadone effects: ciprofloxacin, diazepam, ethanol, fluconazole, urinary alkalinizers.
Decrease methadone effects: phenobarbital, phenytoin, rifampin, many anti-HIV drugs, and urinary acidifiers.

Resources/Guidelines

2005-11-28T12:33:00.000-08:00

From 2001 (Ann Internal Med) and U Michigan Guidelines

SORE THROAT:
Guidelines Ann Internal Med, U Michigan
All adult patients with pharyngitis should be clinically screened for the presence of the Centor criteria:
-tonsillar exudates,
-tender anterior cervical lymphadenopathy,
-absence of cough
-history of fever.
Yes to 3 or 4 criteria: 40 to 60 percent chance of strep throat.
No to 3 or 4 criteria: only 20 percent chance.
Patients with none or one of these criteria should not be tested or treated.

All patients with pharyngitis should be offered appropriate doses of analgesics, antipyretics and other supportive care.

The preferred antimicrobial agent for treatment of acute pharyngitis is penicillin, or erythromycin for penicillin-allergic patients. There is no evidence of group A beta-hemolytic streptococcus resistance to or tolerance of penicillin, and erythromycin resistance rates are low in the United States.

Treatment: Penicillin 250 mg tid-qid or 500 mg bid for 10 days
Alternative: Erythromycin base 333 tid for 10 days
Other alternative: First-gen cephalosporin

These guidelines do not apply to patients with a history of rheumatic fever, valvular heart disease, immunosuppression, recurrent or chronic pharyngitis, or to patients with sore throats not caused by acute pharyngitis. Also, the guidelines should not be used during a known epidemic of acute rheumatic fever or streptococcal pharyngitis or in nonindustrialized countries in which the endemic rate of acute rheumatic fever is much higher than in the United States.

The goal of treatment of strep throat is prevention of rheumatic heart disease.

SINUS PAIN:
Guidelines
Sinusitis: Less than 7 days is usually viral (>90%). Not recommended to start antibiotics unless symptoms have been present more than 7 days. Amoxicillin still preferred.

COUGH:
Guidelines
Bronchitis: Purulent sputum not indicative of bacterial infection

More likely to be pneumonia if heart rate >100, resp >24, and temp >38 C.

90% of acute uncomplicated bronchitis cases are non-bacterial

Albuterol recommended to shorten duration of cough

-At 7 days, 40-60% of albuterol treated patients were still coughing, versus 90% of control.

-Better than antibiotics in studies!
To get the abstracts, go to www.pubmed.gov and type in 1940815 , or 7864949

GENERAL UPPER RESPIRATORY TRACT INFECTION
Guidelines

Almost never bacterial.