Macrolide antibiotics include- Azithromycibn. clarithromycin, dirithromycin, erythromycin and troleandomycin
Refer-  Erythromycin

Interacting drugs - summary

Erthyromycin  +

Alfentanil
 alfentanil clearance decreased and its elimination half-life increased

Anticoagulants
 anticoagulant effect of warfarin or anisindione  increased.
 The risk of bleeding is increased.

Antihistamines/Astemazole/Terfenadine 
  astemazole and terfenadine plasma levels increased, which lead to serious
  cardivascular advere effects

Bromocriptine 
  serum bromocriptine levels increased, resulting in an increase in
  pharmacologic and toxic effects.

Carbamzepine
  carbamazepine toxicity sufficient to require hospitalisation result.
                               
Cyclosporine
  increased Cyclosporine concentrations with renal toxicity occur

Digoxin
 increased serum Digoxin level occur in  a small population of 
  patients(about 10%)  toxic effects occur

Disopyramide
  increased disopyramide plasma level occur. Arrhythmias  and
 increased QTC   have occurred

Ergot alkaloids 
 acute ergotism manifested as peripheral ischemia has occurred

Lincosamide
 under some conditions , coadministration  antagonistic

Macrolide  Antibiotics + Methyl prednisolone
  methylprednisolone clearance decreased

Penicillins 
  In vitro tests and clinical studies demonstrated both                     
   antagonism and synergism with coadministration.

Theophylline
  increased Theophyline serum levels with toxicity are possible.
  Decreased  erythromycin levels  occur

Triazolam  
  Triazolam bioavailability increased, resulting in CNS depression

Lovastatin 
   severe myopathy or rhabdomyolysis occur with concurrent administration

Cisapride 
   in vitro indicate that troleandomycin, erythromycin and clarithromycin
   markedly  inhibit cytochrome p450 IIIA,mainly responsible for
   metabolism of cisapride.
   Concurrent use is contraindicated  

Vinblastine  
   cause toxicity of vinblastine. Severe myalgia, neutripenia and 
   constipation      

Tacrolimus
  these agents increase tacrolimus blood levels

Respiratory tract infections

Macrolide antibiotics include- Azithromycin. clarithromycin, dirithromycin, erythromycin and
troleandomycin

Refer-  Erythromycin

INFORMATION-UPDATE

ERYTHROMYCIN -

Patients who are prescribed erythromycin concurrently with certain commonly used
medicines are at an increased risk of sudden death from cardiac diseases.

Such a risk does not exist with other antibiotics such as amoxycilin.

Prescribers should avoid administration of erythromycin with the following commonly
used drugs-

Amitriptyline, Chloroquin, Chlorpromazine,  Cisapride,  Doxepin,  Haloperidol, Impipramine,

Pimozide,   Quinidine,  Quinine,   Salatol,   Sparfloxacin,   Spiramycin,  Thioridazine  (MIMS)

Local- venous irritation and phlebitis have occured with parentral administration, but the risk of
administration may be reduced if the infusion is given slowly.

Special senses- isolated reports of reversible hearing loss occuring in patients with renal or heaptic
insufficiency in elderly (> 50 years old) and in those receiving high doses ( > 4g.day).

Hypersensitivity- serious allergic reactions including anaphylaxis have occured. Mild reactions include
 rashes with or without pruritus, bullous fixed eruptions and eczema.

GI- most frequent dose-related side effects following oral use include abdominal cramping and
discomfort with erythromycin therapy has occurred

Hepatic- Hepatotoxicity is most commonly associated with erythromycin estlolate

Cardiovascular- rarely, production of arrhythmias, including ventricular tachycardia, and torse de pointes  in individuals with prolonged QT intervals

 

Hypersens to erythromycin.History of jaundice.

Special precautions:
Cholestatic hepatitis & reversible abnormalities in LFT  may be associated with prolonged or
repeated therapy. History of hepatic disorders. Pregnancy, lactation.

Superinfection- use of antibiotics (especially prolonged or repeated therapy) may result in bacterial
overgrowth of nonsusceptible organisms. Take appropiate measures if superinfection occurs.

Warnings-
Pseudomembranous colitis- has occured with virtually all broad spectrum antibiotics. Consider its
diagnosis in patients who develop diarrhea in association with antibiotic use.

Hepatotoxicity- erythromycin administration has been associated with the frequent occurrence of
cholestatic hepatitis.
Symptoms may include malaise, nausea,vomiting, abdominalcramps and fever.Although initial
symptoms have developed after a few days of treatment, they genearlly have followed 1 or 2 weeks
of continuous therapy.
Symptoms reappear promptly, usually within 48 hours after the drug is administerd to sensitive persons.

Hypersensitivity- seriousallergic reactions including anphylaxis have occurred

Hepatic function impairment- exercise caution in administering to patients with impaired hepatic
function. There have reports of hepatic dysfunction with or without jaundice.

Pregnancy- safety for use use during pregnancy has not been established

Lactation- Erythromycin is considered compatible with breast feeding by the American Academy of
Pediatrics

Dosage:
 Usual dosage- Adults - 250mg(or  400mg ethyl succinate)   every  6 hours or 500mg
every  12 hours or  333mg every  8 hours. May increase upto more than  4g/day, according
to severity of infection.  If twice a day is required,the recommended dose   500mg every 12 hours.
Children-
 30 to 50mg/kg/day(15 to  25mg/lb/day/) in  divided doses. For more severe infections,
dosages may be doubled. Proper dosage is determined by age, weight and severity of  infection.

Overdosage-

  Symptoms                                                            

Nausea, vomting, epigastric distress,and diarrhea .Severity is dose related.                                               
                                
  Treatment
                                                                       
  1. Induce prompt elimination of unabsorbed drug
 2. However, unless 5 times the normal single dose has been ingested , GI decontamination should not
      be necessary.
3. Hemodialysis and peritoneal dialysis are not particularly  effective.

Missed dose-

1. If you miss a dose of this medicine, take it as soon as possible.
2. However, if it is almost time for next dose, skip the missed dose and go back to your regular dosing
    schedule.
3. Do not double doses.  

 

Eosinophilia - ( 290 )

Many diseases are encountered where blood or tissue eosinophillia are increased. Eosinophils develop in the bone
marrow similar to neutrophils. Their characterstic red-staining ganules contain a unique perioxidase


Drugs causing adverse reactions-  ( 585 )
-
1. Erythromycin estolate
2. Sulfonamides
3. Chlorpropamide
4. p-aminosalicylic acid
5. Imipramine
6. Nitrofurantoin
7. Procarbazine
8. Methotrexate


 

1. Take preferably on an empty stomach at least 1 hour before or 3\2 hours after meals.
2. If GI upset occurs, may be taken with food. Erythromycin estolate, ethylsuccinate and certain
    brands  of erythromycin base enteric coated tablets may be taken without regards to meals.
2. Complete full course of therapy; take until finished.
3. Take at evenly spaced intervals during the day, preferably round the clock
4. Notify physician if nausea, vomiting, darrhoea, or stomach cramps, severe abdominal pain,
    yellow discoluration of skin or eyes, darkened urine, pale stools, or unusual tiredness occurs.

5. Allergies- Tell your doctor if you have ever had any unusual or allergic reactions to eryhthromycin
    or other related medicines such as azithromycin or clarithromycin.  Also tell your doctor  if your are
     allergic to any  other substances such as foods, preservatives or dyes.

6. Pregnancy-  none of the erythromycins has been shown to cause birth fefects or other problems in
    human babies.

7. Breast feeding-  erythromycins have not not been shown to cause problems in nursing babies  
       
8. Children-  has not been shown to cause different side effects or problems in children than it does in
     adults.  
   
9. Elderly-  older adults maybe at at increased risk of hearing loss especially if they are taking high
    doses of erythromycin and or have kidney or liver disease

10. Other medicines- tell your doctor if you are taking any of the following-
    
      Acetaminophen or
      Amiadarone or
      Anabolic steroids or
      Androgens or
      Antithyroid agents for overactive thyroid or
      Carmustine or
      Chloroquine or
      Dantrolene or
      Daunorubicin or
      Disulfram or
      Divalproex or
      Estrogen female  hormones or
      Gold salts or
      Hydroxychloroquine or
      Mercaptopurine or
      Methotrexate  or
      Methyldopa or
      Naltexone or
      Oral contraceptives or
      Other anti-infectives by mouth or by injection or
      Phenothiazines  or
      Phenytoin or
      Plicamycin or
      Valproic acid  -use of these medicines with erythromycin especially erythromycin estolate may
       increase the chance of liver problems

      Aminophylline or
      Caffeine or
      Oxytriphylline or
      Theophylline - use of these medicines with erythromycin may increase the chance of side effects
       from aminophylline , caffeine , oxtriphylline or theophylline

      Astemizole or
      Tefandine - use of astemizole or terfenadine with eryhtromycin may cause heart problems such as
       irregular heart beats , these medicines should not be used together

      Cabamazepne - use of carbamazepine with reythromycin may increae the side effectsor increase
      the chance liver problems

      Chloramphenicol  or
      Clindamycin or
      Lincomycin - use of these medicines with erythromycin may decrease the effectiveness of other
        antibiotics

      Cyclosporine or
      Warfarin - use of any of these medicines with erythromycin may increase the side effects  of these
       medicines
      
11.  Other medical problems- presence of other medical problems may afect the use of erythromycin-

       Heart disease - high dose of erythromycin may increase the chance of side effects in patients with
       a history of irregular heart beat.

       Liver disease- erythromycin especially estolate may increase the chance of side effects involving
       the liver

       Loss of hearing- high dose of eryhthromycin may on rare occassions cause hearing loss,
       especially if you  have kidney or liver disease.         

13. Missed dose-
    If you miss a dose of this medicine take it as soon as possible. However if it is almost time for your
    next dose  go back to your regular dosing schedule.
    Do not double doses.

14. Avoid administration of erythromycin with the following used drugs-
   
      Amitriptyline,   Chloroquine,   Chlopromazine,  Cisapride,   Doxepin,  Haloperidol,
     
      Imipramine,  Pimozide,  Quinidine,  Quinine,  Solatol,  Sparfloxacin,  Thioridazine

 

Absorption affected to various extent for different esters.

Pregnancy:
 Safety for use during has not been established. Use only when clearly needed.

Lactation:
 Erythromycin is excreted in breast milk. It is considered as compatible by the American Academy
  of Pediatrics