Anaphylaxis

Anaphylaxis is a hypersensitive reaction due to contact through allergens. These allergens induce an immediate immune response that is life threatening in most occasions. Anaphylactic reactions produce various clinical symptoms such as urticaria, respiratory congestion and gastrointestinal disturbances. Anaphylactic response is caused by certain type of compounds which may include proteins, pollen, venom, hormones and also some food extracts. The immunoglobulin E or IgE is responsible for the onset of anaphylactic reaction when exposed to an allergen.

Mechanism of anaphylactic reaction

A series of reactions take place in the body when anaphylaxis is triggered. The IgE which has a half-life of two days, binds to the fragment crystallizable or FC receptor part of the basophils and mast cells. This process is activated when the person comes in contact with an allergen which in turn mediates cellular de granulation and their release of biogenic amines such as histamine and serotonin. The effects of these biogenic amines may include the smooth muscles which generally constrict at the bronchiolar region and broncho capillary venules. It also causes the arteriole dilation.

Anaphylactic responses are of different types and are associated with allergen sources of different kinds such as pollen, food, insects and also some drugs. It happens because of the antigen contact to which the patient had been previously exposed. This type of antigen is also called an allergen. Systemic anaphylaxis is a serious condition in which the mast cells of the connective tissue become activated resulting in dangerous effects such as airway obstruction, swelling of the epiglottis and ultimately suffocation. Systemic anaphylaxis proceeds into another condition called anaphylactic shock which happens because of suffocation induced by the respective allergen. In addition to these, anaphylaxis may also result because of extreme physical exercise. This condition is also called exercise induced urticaria. Allergies to food like eggs and milk are common among infants. Other than these, underlying conditions such as hay fever, asthma and eczema may also induce anaphylaxis if untreated.

Anaphylactic shock is widely reported in people after consuming foods such as peanuts and Brazil nuts. Such food products induce the anaphylactic reaction in an instant causing severe discomfort and sometimes death. Many people also experience anaphylactic reactions because of penicillin administration. Some reactions of anaphylaxis also include excess production of mucous in the mouth, nose and throat. Atopic patients are highly susceptible to anaphylaxis. Patients having an underlying atopic condition produce high amount of IgE antibodies and hence they must be monitored carefully.

Diagnosis of Anaphylaxis

Anaphylactic reaction is diagnosed based on clinical symptoms such as skin rash (insect bites), hoarse voice, chest congestion, breathing difficulty, diarrhea, vomiting and abdominal cramps. Identification of the source is the predominant factor in the diagnosis of anaphylactic reactions. Thorough examination of the cause with immediate life saving measures must be done. Anaphylaxis can be fatal if not managed properly.

Anaphylaxis Treatment

Avoid foods that induce the condition. In the case of anaphylactic reaction, medical attention must be sought immediately. Oral medications such as Benadryl or diphenhydramine are given. EpiPen or injectable epinephrine is the drug of choice to control the anaphylactic reaction. Intravenous antihistamine drugs and oral steroids are given for a period of time to prevent the reoccurrence of the anaphylactic reactions.

Immunologist

An Immunologist can be described as a medical specialist trained to prevent, diagnose, manage and treat diseases that result from abnormalities of the immune system. Immunologists are highly qualified and trained to treat immune system disorders such as allergies, asthma, inherited immunodeficiency diseases and autoimmune diseases. Clinical immunologists and allergy specialists undergo similar training as with any other medical specialists. After completion of four years of premedical education at a college or university, they receive at least four years of medical school education. After receiving general training in internal medicine, they receive additional training in immunology and allergy areas. Immunologists are involved in a gamut of work areas, in hospitals, private practice, diagnostic immunology laboratories, research centers and industrial houses. The medical immunologist or allergy specialist primarily identifies and treats the diseases that result from abnormalities of the immune system.

• Patients are referred by a general physician for further diagnosis, confirmation and management of clinical disorders of the immune system.
  
• Patients seeking the advice of an immunologist for education regarding disorders of the immune system.
  
• Patients suffering from life threatening allergies such as anaphylaxis.
  
• When food or occupational allergy is suspected, the patient is referred to an immunologist.
  
• When a physician contemplates immunotherapy for treatment of allergic diseases, the patient is sent to the immunologist.
  
• Patients suffering from asthma exhibiting continuing poor control despite regular use of asthma medication.
  
• Patients with unexplained inflammation such as fevers of unknown origin, unexplained fevers, weight loss.
  
• For investigation of recurrent or unusual opportunistic infections.
  

List of general Antibiotics

Antibiotics are primarily used to treat bacterial infections. They may have secondary uses - treatment of the Syndrome of Inappropriate Antidiuretic Hormone (SIADH) secretion with Declomycin. Some antibiotics are also used to prevent infection (antibiotic prophylaxis) before any surgery or in the case of weakened immune systems. There was a study which indicated that about 300 million prescriptions for antibiotics are issued every year in the US alone and the wide spread use or abuse of the antibiotics is a serious issue. For example, an antibiotic can seriously deplete the normal intestinal micro flora which can result in vaginal yeast infection in susceptible women. Indiscriminate use of antibiotics can bring about increased incidences of Streptococcal disease in children apart from enhanced drug resistance.

Antibiotic medications can be categorized as either bactericidal or bacteriostatic. Bactericidal antibiotics, like penicillins and cephalosporins, directly kill bacteria. On the other hand, bacteriostatic antibiotics, such as erythromycin, inhibit bacterial growth and multiplication, thereby allowing the immune system to manage and resolve the infection.
Prophylactic antibiotics drugs are given to individuals who are at high risk of infection but are not currently infected. Sometimes, Antibiotics are administered before surgery, to patients with weakened immune systems, or to prevent infections in certain medical conditions. This is in contrast to Therapeutic Antibiotic Treatment where an bacterial infection has been diagnosed which requires specific antibiotic drug to combat the infection.

Antibiotics Classification: Antibiotics are classified under many categories. Commonly they are grouped based on chemical structure and Antibiotics within the same class exhibit similar kind of effectiveness, allergic potential and toxicity. The exhaustive list below also contains drug allergy or other reactions possible for susceptible individuals as appropriate under each class.


Other types of classification:
Bacterial Spectrum: Broad Spectrum Antibiotics are capable of targeting many types of bacteria while narrow spectrum antibiotics target specifically a single class of bacteria. It is generally preferable to use a specific antibiotic for the specific class of bacteria.

Type of Activity: Bactericidal drugs are intended to kill bacteria while bacteriostatic drugs are intended to inhibit the growth of bacteria.

Broad Spectrum Antibiotics: According to a Swiss Study, this class of Antibiotics which act against Gram+ and Gram- bacteria is prone to misuse. Broad Spectrum Antibiotics - specifically the antipseudomonal agents (i.e. cefepime, ceftazidime, ciprofloxacin, imipenem, meropenem, piperacil lin/tazobactam) plus trovafloxacin were found to be misused.

The following list shows the generic names of common antibiotics prescribed and available under various trade names in the US. We have broadly classified them under the common 'family' names.

Broad Spectrum Penicillins / Amoxicillin : Penicillin Family Antibiotics List

Penicillins - one of the oldest type of broad spectrum antibiotics, share common chemical structure with Cephalopsorins. They are classified as Beta-lactam antibiotics. Aminopenicillins such as Ampicillin and Amoxicillin have extended spectrum of action. Extended Spectrum Penicillins are effective against a broad range of bacteria including Pseudomonas Aeruginosa which affect patients with weakened immune systems.

The Penicillin family of antibiotics includes various types of antibiotics that share a similar chemical structure and mechanism of action. Here is a list of some well-known antibiotics within the Penicillin family:

• Penicillin G (Benzylpenicillin) : One of the earliest and most commonly used antibiotics, effective against many bacterial infections.
  
• Penicillin V (Phenoxymethylpenicillin) : Often used to treat streptococcal infections, especially those involving the throat.
  
• Amoxicillin : A widely prescribed broad-spectrum antibiotic used to treat a range of bacterial infections.
  
• Ampicillin : Similar to amoxicillin but with a broader spectrum of activity, effective against both Gram-positive and some Gram-negative bacteria.
  
• Oxacillin : A penicillinase-resistant penicillin used to treat infections caused by penicillin-resistant Staphylococcus aureus (MRSA).
  
• Methicillin : Another penicillinase-resistant penicillin used against penicillin-resistant Staphylococcus aureus, though it's not commonly used due to side effects.
  
• Piperacillin : An extended-spectrum penicillin often used in hospitals for severe infections.
  
• Ticarcillin : Another extended-spectrum penicillin used for treating various infections, especially those involving Pseudomonas aeruginosa.
  
• Carbenicillin : Effective against Gram-negative bacteria, especially Pseudomonas species.
  
  
• Augmentin (Amoxicillin/Clavulanic Acid) : A combination antibiotic that includes amoxicillin and clavulanic acid, used to treat a broader range of infections.
  

  Dosage for Augmentin: For Adults and Children:
  The usual dose of Augmentin is 250 mg/125 mg to 875 mg/125 mg twice a day, depending on the severity of the infection. The tablet strength is expressed as the amount of amoxicillin/clavulanic acid in milligrams.

  
  

  For Children (Dosage can vary based on weight):
  The pediatric dose is typically calculated based on the child's weight and is expressed as milligrams of amoxicillin/clavulanic acid per kilogram (mg/kg) of body weight. The dose is usually divided into two or three equal doses spread throughout the day.

  
  
• Unasyn (Ampicillin/Sulbactam) : Similar to Augmentin, this combination includes ampicillin and sulbactam, extending its activity against beta-lactamase-producing bacteria.
  

Allergic reactions are common with Penicillins for susceptible individuals. Cephalosporins can cause seizures or affect the blood clotting time for susceptible patients.

• Ampicillin
  
• Bacampicillin
  
• Carbenicillin Indanyl
  
• Mezlocillin
  
• Piperacillin
  
• Ticarcillin

Penicillins and Beta Lactamase Inhibitors

• Amoxicillin-Clavulanic Acid
  
• Ampicillin-Sulbactam
  
• Benzylpenicillin
  
• Cloxacillin
  
• Dicloxacillin
  
• Methicillin
  
• Oxacillin
  
• Penicillin G
  
• Penicillin V
  
• Piperacillin Tazobactam
  
• Ticarcillin Clavulanic Acid
  
• Nafcillin
  
• Procaine Penicillin - Injectable form of penicillin that contains an anesthetic to reduce the pain of the injection. Procaine Penicillin dosage is usually between 600000 to 1 million units per day Intramuscular (IM) for about 10 days for most Upper respiratory tract infection and other simpler bacterial infections. P Penicillin must never be administered intravenously as it can result in anaphylactic shock.
  

Cephalosporins

Cephalosporins, one of the largest classes of Antibiotics are used to treat a long list of bacterial infections from around the year 1950. The latest in this class, Ceftaroline is a new fifth generation Cephalosporin - a broad spectrum Antibiotics that shows promise against Gram + bacteria including Methicillin Resistant Staphylococcus Aureus (MRSA),Vancomycin Intermediate S.Aureus (VISA), Vancomycin Resistant S.Aureus (VRSA)and Heteroresistant VISA (hVISA).

• Cephalosporin I Generation Antibiotics
  
• Cefadroxil
  
• Cefazolin
  
• Cephalexin
  
• Cephalothin
  
• Cephapirin
  
• Cephradine

Cephalosporin II Generation Antibiotics

• Cefaclor
  
• Cefamandol
  
• Cefonicid
  
• Cefotetan
  
• Cefoxitin
  
• Cefprozil
  
• Ceftmetazole
  
• Cefuroxime
  
• Loracarbef

Cephalosporin III Generation Antibiotics

• Cefdinir
  
• Ceftibuten
  
• Cefoperazone
  
• Cefixime
  
• Cefotaxime
  
• Cefpodoxime proxetil
  
• Ceftazidime
  
• Ceftizoxime
  
• Ceftriaxone

Cephalosporin IV Generation Antibiotics

• Cefepime
  
• Cefluprenam
  
• Cefozopran
  
• Cefpirome
  
• Cefquinome
  

Fourth generation Cephalosporin antibiotics are effective in the treatment of Encephalitis and Meningitis as they cross the blood-brain barrier.

Cephalosporin V Generation Antibioticsor New Generation Cephalosporins - NGCs

• Ceftolozane
  
• Ceftaroline
  
• Ceftobiprole
  

The New Generation Cephalosporins show considerable efficacy against a host of bacteria - from MRSA to respiratory pathogens like Streptococcus Pneumoniae, Haemophilus Influenzae and Moraxella Catarrhalis.
β lactam antibacterial resistance: These fifth generation Cephalosporins inhibit the cell wall synthesis of Penicillin Binding Proteins (PBPs). For example, Ceftaroline's anti MRSA efficacy stems from its high affinity for the MRSA associated (Penicillin Binding Proteins)PBP2a. It may have affinity greater than 256 times over other β lactams.

Ceftaroline is effective against the following:

Gram Positive Bacteria which cause skin infections:
Methicillin Resistant Staphylococcus Aureus (MRSA) and resistant isolates
Streptococcus Pyogenes
Streptococcus Agalactiae

Gram Positive Bacteria which cause Community Acquired Bacterial Pneumonia (CABP):
Streptococcus Pneumoniae
Staphylococcus aureus(methicillin susceptible isolates)

Gram Negative Bacteria:
Klebsiella Pneumoniae
Klebsiella Oxytoca
Escherichia Coli
Haemophilus Iinfluenzae
Escherichia Coli

Macrolides and Lincosamines

Macrolide Antibiotics have macrocyclic lactone chemical structure. Erythromycin and the newer antibiotics belonging to this broad spectrum class - Azithromycin and Clarithromycin are widely used for their higher level of lung penetration. Erythromycin may rarely result in Myasthenia gravis while Azithromycin may rarely result in Angioedema (Patches of swelling of the skin, mucus membranes and internal organs), Anaphylaxis (hypersensitive reaction due to contact through allergens) or other allergic reactions.

• Azithromycin
  
• Clarithromycin
  
• Clindamycin
  
• Dirithromycin
  
• Erythromycin
  
• Lincomycin
  
• Troleandomycin

Quinolones and Fluoroquinolones

Fluoroquinolones are synthetically manufactured broad spectrum Antibiotics. Lomefloxacin is reported to cause increased photosensitivity and in some cases may result in convulsion.

• Cinoxacin
  
• Ciprofloxacin
  
• Enoxacin
  
• Gatifloxacin
  
• Grepafloxacin
  
• Levofloxacin
  
• Lomefloxacin
  
• Moxifloxacin
  
• Nalidixic acid
  
• Norfloxacin
  
• Ofloxacin
  
• Sparfloxacin
  
• Trovafloxacin
  
• Oxolinic acid
  
• Gemifloxacin
  
• Perfloxacin

Beta lactam Antibiotics: Carbepenems

Imipenem-Cilastatin
Meropenem

Monobactams
Aztreonam

Aminoglycosides : These antibiotics are specifically used to target aerobic, Gram-negative bacteria. Generally useful against Pseudomonos, Acinetobacter and Enterobacter amongst others. Streptomycin is effective to control tuberculosis causing mycobacteria. Antibiotic treatment with Aminoglycosides often involves the use of another antibiotics for overall better synergetic effect.

• Amikacin
  
• Gentamicin
  
• Kanamycin
  
• Neomycin
  
• Netilmicin
  
• Streptomycin
  
• Capreomycin Sulfate
  
• Tobramycin
  
• Paromomycin

Details on Specific Antibiotic Therapy

Gentamicin: Gentamicin is the antibiotic of choice for the treatment of some kind of blood infections caused by gram negative bacilli like the following:

• Citrobacter freundii
  
• Acinetobacter species
  
• Enterobacter species
  
• Escherichia coli
  
• Klebsiella pneumoniae
  
• Proteus mirabilis
  
• Providencia stuartii
  
• Pseudomonas Aeruginosa
  
• Serratia species
  

Gentamicin is often used along with beta-lactam antibiotics for better efficiency.

Conventional Dosage: It should be noted that a typical dosage of Gentamicin is usually given 2 to 3 times a day by IV (intravenous) or IM (intramuscular) injections to achieve peak blood concentration between 5.0 μg/mL and 12.0 μg/ml. The dosage mentioned here depends on the type of infection and on other factors like the patient's renal function. Gentamicin is sometimes given at a higher dose than the suggested common dosage - 5-7mg/kg of body weight once per day - termed as pulse dosing for patients with good tolerance and good renal function. Risk of excessive dosage in the case of Gentamicin is Ototoxicity (damage to the inner ear) and Nephrotoxicity (damage to kidneys).

Glycopeptides
Teicoplanin
Vancomycin

Tetracyclines

• Demeclocycline
  
• Doxycycline
  
• Methacycline
  
• Minocycline
  
• Oxytetracycline
  
• Tetracycline
  
• Chlortetracycline

Tetracyclines are not normally prescribed for children under the age of 8 due to the permanent tooth discoloration these drugs cause.

Sulfonamides

• Mafenide
  
• Silver Sulfadiazine
  
• Sulfacetamide
  
• Sulfadiazine
  
• Sulfamethoxazole
  
• Sulfasalazine
  
• Sulfisoxazole
  
• Trimethoprim-Sulfamethoxazole
  
• Sulfamethizole

Rifampin

Rifabutin
Rifampin also known as Rifampicin (Rifadin)
Rifapentine

Oxazolidonones

Linezolid
Streptogramins
Quinopristin Dalfopristin


Other Antibiotics

Bacitracin: Bacitracin belongs to a class of antibiotics known as polypeptides. Bacitracin is effective against a variety of bacteria, particularly Gram-positive bacteria.
Mechanism of Action:
Bacitracin works by interfering with the bacteria's ability to form cell walls. Specifically, it inhibits the formation of peptidoglycan, an essential component of bacterial cell walls. Without a properly formed cell wall, bacteria are unable to maintain their structural integrity and eventually die.

Uses:
Skin Infections : Bacitracin is commonly used as a topical antibiotic ointment or cream to treat minor skin infections such as cuts, scrapes, and minor burns. It helps prevent bacterial growth in the affected area, allowing the body to heal more effectively. Eye Infections : Bacitracin ointment is also used in the treatment of certain eye infections, such as bacterial conjunctivitis (pink eye). It is applied to the inner eyelid to help fight the infection. Other Infections : Bacitracin can be used in other types of infections, such as those affecting the respiratory tract or urinary tract, but it is less commonly used for these purposes compared to other antibiotics.

Administration:
Topical : Bacitracin is most commonly available as a topical ointment or cream. It should be applied directly to the affected area of the skin. Before application, the area should be cleaned and dried thoroughly. Ophthalmic : Bacitracin ointment for the eyes should be applied as directed by a healthcare professional. It is usually applied to the inner eyelid several times a day, depending on the severity of the infection. Side Effects : Bacitracin is generally considered safe when used topically or as directed. However, like any medication, it can cause side effects in some individuals. Common side effects include:

Skin irritation, redness, or itching at the application site
Allergic reactions (rare but possible)
Contact dermatitis (inflammation of the skin due to an allergic reaction or irritation)
Precautions and Considerations :

Bacitracin is for external use only and should not be ingested.
It should not be used on deep cuts, puncture wounds, animal bites, or serious burns without consulting a healthcare professional.
Individuals with known allergies to bacitracin or any component of the medication should avoid its use.
Pregnant or breastfeeding women should consult with a healthcare professional before using bacitracin.

Chloramphenicol : Chloramphenicol is another strong broad spectrum antibiotic. Chloramphenicol may be the antibiotic of choice for the following conditions :
Bacterial meningitis: Chloramphenicol can be used to treat bacterial meningitis, which is an infection of the membranes that surround the brain and spinal cord.
Typhoid fever: Chloramphenicol can be used to treat typhoid fever, which is a bacterial infection that can cause high fever, headache, and gastrointestinal symptoms.
Rickettsial infections: Chloramphenicol can be used to treat rickettsial infections, which are bacterial infections that are spread by ticks, lice, fleas, and other insects.
Bacterial conjunctivitis: Chloramphenicol can be used to treat bacterial conjunctivitis, which is an infection of the eye that can cause redness, discharge, and irritation.
The recommended dosage of Chloramphenicol will depend on the specific condition being treated, the age and weight of the patient and other individual factors.

Dosage:
For bacterial meningitis in children: The recommended dosage is 50-100 mg/kg/day, given in 4 divided doses.
For typhoid fever: The recommended dosage is 50-75 mg/kg/day, given in 4 divided doses for 14 days.
For bacterial conjunctivitis: The recommended dosage is 1-2 drops of a 0.5% ophthalmic solution in the affected eye(s) every 2-4 hours.
For acne: The recommended dosage is 50-100 mg orally, 2-4 times daily, for several weeks.

Caution: Some of the common side effects of Chloramphenicol include - Nausea, vomiting, Diarrhea, Headache, Dizziness, Rash, Blood disorders, such as anemia or low white blood cell count. In rare cases, Chloramphenicol can also cause serious side effects, such as aplastic anemia, which is a condition where the bone marrow stops producing new blood cells.