Download Treating HCV in Injection Drug Users on Methadone

Bugs and Drugs:
A Review of Infectious
Diseases and Substance Use
Diana L. Sylvestre, MD
Assistant Clinical Professor of Medicine
University of CA, San Francisco
Executive Director
Organization to Achieve Solutions in Substance-Abuse
(O.A.S.I.S.)
Acute Bacterial Infections
• Responsible for 60% of hospital
admissions among IDUs
• Challenges
– Differentiate occult infection from
intoxication/withdrawal
– Recognize atypical presentations
• Predisposing factors
– Defective mucociliary funtion
– Malnutrition
– Altered cell-mediated immunity
Cellulitis
• Staph most common, strep is next
• Predisposing behaviors
– Mixing drugs with saliva
– Licking needles
– Poor injecting and personal hygiene
• Tissue necrosis
– Vasoactive opiates
– Cocaine-induced vasospasm
– Other contaminants
Necrotizing Fasciitis
– Streptococcus, mixed aer/anaerobes
– More likely with “muscling” or “skin
popping”
– Classic presentation: pain way out of
proportion to findings soon after
injecting
– Medical emergency
– Note: increasing incidence of
infections in large skeletal muscles,
especially in patients with HIV
Bacterial Infections, cont.
• Wound botulism
– Clostridium toxin causes paralysis
– Classic presentation:
• Dry, scratchy throat, followed by
• Cranial nerve palsies followed by
• Descending paralysis
– Treatment:
• Find the source
• Antibiotics
• Long-term respiratory support
Bacterial Endocarditis
–Fever and heart murmur
–IDUs younger and without
preexisting valvular disease
–>50% staph, ~15% strep
–More likely to require surgery
–HIV does not increase risk
Respiratory Infections
• Predisposing factors:
– Cigarettes
– Alcohol
– Altered MS and loss of gag reflex
– HIV
• Up to 1/3 of IDUs with fever have
pneumonia
• Increased incidence of H flu, S. aureus,
Ps. aeruginosa relative to non-IDUs
Tuberculosis
• IDUs have increased risk of Tb reactivation
– Reason is unknown
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Increased risk of MDR TB
Cough, blood-tinged sputum, malaise
Later: night sweats, wt loss
PPD negative in 25% at diagnosis
1/6 extrapulmonary risk increased to 60-80% in
HIV
TB Recommendations
• Yearly PPD unless previously positive
• PPD positive:
– HIV+: 5 mm
• 12 mo chemoprophylaxis with INH, 300mg/d with B6
– HIV-: 10 mm
• 6 mo chemoprophylaxis with INH/B6
– If PPD+, R/O active TB: CXR, cultures
• INH, rifampin, pyrazinamide: liver toxicity
• Rifampin lowers methadone levels
STDs
• Higher rates of
– Syphilis
• Annual RPR recommended
– HPV
• Increased risk of cervical cancer with certain
serotypes
– Chlamydia and GC
• Cervical culture/DNA, urine screen available
Hepatitis A/B
• HAV: fecal-oral transmission
• HBV: Most common cause of reported cases
of acute hepatitis
• Transmitted sexually, by blood, and vertically
• Chronic infection in <5% adults, >90%
perinatally
Hepatitis D
• Defective virus, only occurs in presence of
active HBV
• More aggressive disease
• HBV vaccination is protective
HIV
• In US:
– 750,000 cases
– 40,000 new infections per year
• 26% due to IDU, 19% male, 6%
female
• 25% of HIV-infected persons in the US are
coinfected with HCV
• 50-93% of HIV-infected IDUs are
coinfected
AIDS
• Over the past few years, the numbers of newly
reported cases of AIDS in IDUs has surpassed
the numbers in MSM
• Women with AIDS:
– 42% from IDU
• Men with AIDS:
– 22% from IDU
• Most common reason for death: liver disease
(HCV)
HIV in IDUs
• Increasing reports of significant HIV
infection rates in non-injection drug users
– Probably sexual transmission
– Disinhibiting effects of:
• Alcohol, amphetamines, cocaine, inhalants
• Substantially increased seroprevalence
rates in crack users
HIV in IDUs
• Among IDUs, the risk of HIV infection increases
with:
– Duration of injection drug use
– Frequency of needle sharing
– Number of sharing partners, especially in shooting
galleries
– Little or no condom use
– Multiple sexual partners
– Comorbid psychiatric conditions such as ASPD
– Use of cocaine in injectable form or smoked as crack
– Use of injection drugs in a geographic location with a
high prevalence of HIV infection.
Preventing Transmission in IDUs
• Needle exchange effective at reducing HIV
transmission and does not increase use of
injection drugs
• Counsel re: heterosexual transmission
• No breastfeeding
HIV Tests
• HIV antibodies appear 2-12 weeks after
infection
• HIV RNA:
– Determine prognosis (primary)
• CD4+ T cell count is best indicator of the
immediate state of immunologic
competence in a patient with HIV
HAART
• Highly-active anti-retroviral therapy
• Has resulted in marked declines in the
majority of AIDS-defining conditions
• HAART involves the use of 3 or more
antiviral medications, typically in 2
categories
Reverse Transcriptase Inhibitors
• NRTI’s: nucleoside analogues
– AZT, ddI, ddC, d4T, 3TC, ABC
– Nonselective, serious side effects
– Methadone may reduce blood levels: ddI, stavudine
• NNRTI’s: non-nucleoside RTIs
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Nevirapine, delarvadine, efavirenz
Very selective for HIV-1 RT
Rash, neuropsychiatric toxicity
Methadone level reduced: nevirapine, efavirenz
Protease Inhibitors
• Saquinavir, indinavir, ritonavir, nelfinavir,
amprenavir
• Ritonavir “boosting” is common
• Lipodystrophy syndrome:
– Hyperlipidemia, insulin resistance
– Fat redistribution
• Methadone level reduced
– Ritonavir, nelfinavir, lopinavir
Hepatitis C
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4 million cases in US, 170 million worldwide
60% of new and existing cases related to IDU
Seroprevalence in IDU 65-96%
Transmitted by blood: needles, syringes,
cottons, cookers, rinsewater
• Sexual transmission rare, ~5%
– STD’s, multiple sexual partners
• Vertical transmission rare, ~5%
Hepatitis C
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8-16% develop cirrhosis after 2 decades
Accelerated disease with HIV
Accelerated disease with EtOH
Drug use not known to accelerate natural
course
HCV Testing
• LFT’s normal persistently in ~1/4 with active disease
• HCV antibody: EXPOSURE, NOT active infection
– ~25% spontaneously clear
• HCV viral load
– Indicates ACTIVE disease, not extent of disease
• HCV genotype
– By far the best predictor of response to therapy
– Determines length of therapy
HCV Treatment
• Cornerstone of treatment is interferon/ribavirin
combination therapy for 24-48 weeks
• Interferon administered by injection
• Ribavirin administered PO
• Outcome measure:
– Sustained virologic response (SVR)
• Lack of virus 6 months after completing therapy
• 54-56% with current therapy
Needlestick Injuries
• Risk of transmission from needlestick injury
is HIV<HCV<HBV:
– 0.3% with HIV
– 1.8% with HCV (6x higher)
– 6-30% with HBV (50x higher)
Vaccinations
• dT every 10 years
– > 5 years if tetanus-prone wound
• HAV
• HBV
• Pneumovax:
– >50, HIV
• Flu