Transcript Adverse effects

Skin Conditions, Parasites and
Fungi
Question
Yeasts are multicelled organisms.
A. True
B. False
B. False - Yeasts are single-celled organisms
about the size of red blood cells.
Physiology of Fungal Growth
 Fungi can be separated into two groups—yeasts and molds.
 Yeasts are single-celled organisms.
 Molds produce long, hollow, branching filaments called
hyphae.
 Normally, the body has yeast colonies on the skin, mucous
membranes, and GI tract.
 Immune mechanisms and competition for nutrients, provided
by the body’s normal bacterial flora, ordinarily keep
colonizing fungi in check.
Fungi can produce disease in humans only
if they can grow at the temperature of the
infected body site.
Fungal
Infections
Some Opportunistic Fungal Infections
 Aspergillosis is a fungus
commonly found in soil,
water, and decaying
vegetation.
 Infection is airborne.
 Candidiasis is a yeast-
like fungus that is almost
always present as part of
the normal population of
organisms in the mouth,
skin, intestinal tract, and
vagina.
 Cryptococcosis, which
usually manifests as
cryptococcal meningitis, is
the most serious of the
fungal infections in
immunocompromised
patients.
 Mucormycosis is a fungal
infection of the sinuses,
brain, or lungs caused by
fungi such as Mucor or
Rhizopus.
Pathophysiology of Fungal Infections
 Blastomycosis is a
chronic infection
characterized by
granulomatous and
suppurative lesions.
 Dermatophytic infections
(tinea, ringworm) are fungal
infections caused by mold-like
fungi called dermatophytes.
Tinea lives on the dead tissues
on the skin and any structures
that grow from the skin (e.g.,
hair or nails).
 Coccidioidomycosis is a
disease of the lungs,
is a fungal
which is common in the  Histoplasmosis
infection that affects the lungs
southwestern United
States and northwestern
Mexico.
or other organs by
dissemination.
 The disease is acquired by
inhaling fungal spores.
Tinea
Infections
Polyene Antifungal Agents
 Polyene antimicrobials include amphotericin B and
nystatin.
 These drugs have high affinity for fungal infections and
are therefore useful for treating systemic fungal
infections.
 Unfortunately, the polyene antifungal drugs also have
the ability to induce severe adverse effects.
Prototype drug: amphotericin B
(Fungizone)
Amphotericin B: Core Drug
Knowledge
 Pharmacotherapeutics
 Treats progressive and potentially fatal systemic
fungal or protozoal infections
 Pharmacokinetics
 Administered: IV or oral. Metabolism: unknown.
T½: 24 hours.
 Pharmacodynamics
 Binds to sterols in fungal cell membranes
Amphotericin B: Core Drug
Knowledge (cont.)
 Contraindications and precautions
 Caution in patients with preexisting anemia,
hypokalemia, and hypomagnesemia
 Adverse effects
 Nephrotoxicity, hypokalemia,
hypomagnesemia, hypochloremia, and
hypocalcemia
Question
Which of the following is the common serious adverse
effects of amphotericin B?
A. Nephrotoxicity
B. Ventricular tachycardia
C. Bronchospasm
D. Cardiac arrest
A. Nephrotoxicity - Amphotericin B has an extensive
adverse effects profile. In fact, some clinicians refer to it as
“amphoterrible.” Nephrotoxicity occurs in more than 40%
of patients receiving amphotericin B.
Azole Antifungal Drugs
 The azole antifungal drugs can be classified into two
subgroups: imidazoles and triazoles.
 Azole antifungal drugs can be used for both superficial
mycoses and more serious systemic mycoses.
Prototype drugs: fluconazole (Diflucan)
ketoconazole (Nizoral)
Metronidazole (Flagyl)
Pathophysiology
Malaria is
caused by
protozoan
parasites of
the genus
Plasmodium.
Pathophysiology (cont.)
 Parasitic diseases
 Amebiasis is most frequently caused by the
microorganism Entamoeba histolytica,
which is passed from host to host by
ingestion of fecally contaminated food or
water.
 Cryptosporidiosis is a diarrheal disease
caused by Cryptosporidium parvum.
 Giardiasis is a common disease caused by a
flagellated protozoan, Giardia lamblia.
Pathophysiology (cont.)
 Trichomoniasis is an infection of the
vagina caused by the parasite
Trichomonas vaginalis.
 Toxoplasmosis is caused by a parasite
found in a variety of animals, especially
cats and birds.
 Pneumocystis jiroveci pneumonia is an
opportunistic lung infection caused by a
parasite of uncertain classification.
Pathophysiology
 Helminthic infections
 Intestinal nematode infections
The common intestinal nematodes are the giant
roundworm, pinworm, threadworm, whipworm,
and pork roundworm.
Roundworms in human stomach:
https://www.youtube.com/watch?v=8Snyr_6jY
Mk

Pathophysiology
 Blood and tissue
nematode
(roundworm)
infections
 Filarial infections are
among the more
serious and debilitating
helminthiases
associated with blood
and tissue nematodes.
Pathophysiology (cont.)
 Cestode Infections
 Tapeworm infections are transmitted in
contaminated raw or improperly cooked fish, beef,
and pork.
https://www.youtube.com/watch?v=-g7TVlWqDJ8
Pork tapeworms can invade other tissues via the
bloodstream.
 Trematode Infections
 Cause schistosomiasis, leading cause of morbidity
and mortality from parasitic disease; vector is small
snail acquired through contaminated water.
Pathophysiology (cont.)
 Ectoparasitic infections
 Scabies is a skin inflammation caused by a
mite, Sarcoptes scabiei.
 Pediculosis is an infestation occurring on
the scalp (pediculosis capitis), trunk
(pediculosis corporis), or pubic areas
(pediculosis pubis).
Antiprotozoan Drugs
 Antiprotozoan drugs are used to treat many
human infections, including amebiasis, giardiasis,
trichomoniasis, toxoplasmosis, and opportunistic
infections, such as PCP.
 Because of an increase in the past decade of
protozoan infections in the United States, many
new antiprotozoan drugs are being developed.
Metronidazole (Flagyl) is the prototype.
Metronidazole: Core Drug
Knowledge
 Pharmacotherapeutics
 Treatment of trichomoniasis, amebiasis, and
giardiasis
 Pharmacokinetics
 Administered: orally, intravenously, and
topically. Metabolism: liver.
 Pharmacodynamics
 Acts against anaerobic bacteria by inhibiting
DNA synthesis
Metronidazole: Core Drug
Knowledge (cont.)
 Contraindications and precautions
 Caution with alcohol or pregnancy
 Adverse effects
 Nausea, vomiting, dry mouth, altered sense
of taste (dysgeusia), anorexia, and
abdominal pain
 Drug interactions
 Ethanol
Metronidazole: Teaching,
Assessment, and Evaluation
 Patient and family education
 Create teaching plans that focus on explaining the
potential adverse effects.
 When used for STI’s explain that partners must be
treated as well
 Discuss the importance of refraining from
ethanol or disulfiram use during therapy.
Question
Metronidazole should be used with caution in the
patient who is dependent on alcohol.
A. True
B. False
A. True because of the capacity for a disulfiram-like
interaction (i.e., nausea, vomiting, headache, and chest
pain), ingestion of metronidazole and alcohol should be
separated by at least 1 day.
Antiectoparasitic Drugs
 Antiectoparasitic drugs include permethrin, lindane,
crotamiton, malathion, and pyrethrins \.
 These are topical drugs with local action.
 Although they can eradicate the parasite, they have
minimal effect on the pruritus (itching) that
frequently accompanies ectoparasitic infections.
 Resistance is problematic with all of the topical drugs.
Prototype drug: permethrin (Nix)
Permethrin: Core Drug Knowledge
 Pharmacotherapeutics
 Scabicide and pediculicide
 Pharmacokinetics
 Administered: topically. Excreted:
kidneys.
 Pharmacodynamics
 Disrupts the parasite’s nerve cell
membrane, resulting in paralysis and
death.
Permethrin: Core Drug Knowledge
(cont.)
 Contraindications and precautions
 Hypersensitivity
 Adverse effects
 Burning, itching, numbness, rash, redness,
stinging, swelling, or tingling of the scalp
 Drug interactions
 No drug–drug interactions are known to occur
with permethrin.
Permethrin: Planning and
Interventions
 Maximizing therapeutic effects
 Instruct that permethrin is for external use only, and
encourage the patient to use it exactly according to
directions.
 Okay to use diphenhydramine (Benadryl) for itching
 Minimizing adverse effects
 Keep the drug out of the reach of children, who may ingest
it accidentally.
Permethrin: Teaching, Assessment,
and Evaluation
 Patient and family education
 Emphasize the potential adverse effects of permethrin.
 Tell the patient to leave the permethrin cream on the skin
for 8 to 14 hours.
 Ongoing assessment and evaluation
 After-treatment evaluations consist of monitoring for signs
of successful treatment (eradication) or failure
(reinfection).
Acne
Vulgaris
Acne
 Acne is the most common skin condition in the
United States.
 Without treatment, dark spots and permanent scars
can appear on the skin as acne clears.
 Symptoms:
 Blackheads
 Whiteheads
 Papules
 Pustules (what many people call pimples)
 Cysts
 Nodules
Cause of Acne
 Acne appears when a pore in the skin clogs.
 This clog begins with dead skin cells.
 Normally, dead skin cells rise to surface of the pore,
and the body sheds the cells.
 When the body starts to make lots of sebum, oil that
keeps our skin from drying out, the dead skin cells can
stick together inside the pore.
 Instead of rising to the surface, the cells become
trapped inside the pore.
Causes of Acne (cont’d)
 Sometimes bacteria that live on our skin, p. acnes,
also get inside the clogged pore.
 Inside the pore, the bacteria have a perfect
environment for multiplying very quickly.
 With loads of bacteria inside, the pore becomes
inflamed (red and swollen).
 If the inflammation goes deep into the skin, an
acne cyst or nodule appears.
Treatment for Acne
 Topical
 There are many topical acne treatments. Some topicals
help kill the bacteria. Others work on reducing the oil.
The topical medicine may contain a retinoid,
prescription-strength benzoyl peroxide, antibiotic, or
even salicylic acid.
 Procedures
 Lasers and other light therapies
 Chemical peels
 Acne removal: drainage and extraction
Treatment for Acne
 Systemic Medications
 Birth control pills and other medicine that
works on hormones (can be helpful for
women).
 Isotretinoin (the only treatment that works
on all causes acne).
 Antibiotics (helps to kill bacteria and reduce
inflammation).
Prototype: Tetracycline
Tetracyclines
 The tetracyclines were developed as semisynthetic
antibiotics based on the structure of a common soil
mold.
 They are broad-spectrum antibiotics that affect both
gram-positive and gram-negative bacteria.
 Over the years, major resistance has developed to
tetracyclines.
Tetracycline: Core Drug Knowledge
 Pharmacotherapeutics
 Rickettsia species, Mycoplasma pneumoniae, and
Chlamydia trachomatis
 Pharmacodynamics
 Inhibits or retards the growth of bacteria but does not kill
them
 Contraindications and precautions
 Allergy, pregnancy, or lactation
 Side/Adverse effects
 GI upset, Photosensitivity, and Rash. Tooth staining.
Challenge Question
Tetracycline should not be administered with milk or
antacids.
A. True
B. False
A. True - Tetracycline forms an insoluble chelate with
aluminum, bismuth, calcium, iron, magnesium, and zinc
salts, which are frequently an ingredient in antacids.
Homework Assignment
 Please do Shadow Health Intermediate
Case, Tina Jones.
 You don’t need to submit anything to the
Canvas Assignment – that provides a
placeholder for completion points. I will
review your assignment in Shadow Health.