358	A n t i b i o t i c E s s e n t i a l s

POST-EXPOSURE PROPHYLAXIS

Some infectious diseases can be prevented by post-exposure prophylaxis (PEP).. To be ­maximally effective, PEP should be administered within 24 hours of the exposure, since the effectiveness of prophylaxis > 24 hours after exposure decreases.. PEP is usually reserved for persons with close/ intimate contact with an infected individual.. Casual contact does not warrant­ PEP..

Table 6.3. Post-Exposure Prophylaxis

	Usual	Preferred	Alternate
Exposure	Organisms	Prophylaxis	Prophylaxis	Comments
Meningitis	N..	Any quinolone	Minocycline	Must be administered
	meningitidis	(PO) × 1 dose	100 mg (PO)	within 24 hours of close
			q12h × 2 days	face-to-face exposure to
			or	be effective.. Otherwise,
			Rifampin 600 mg	observe and treat if
			(PO) q12h × 2	infection develops..
			days
	H.. influenzae	Rifampin	Any quinolone	Must be administered within
		600 mg (PO)	(PO) × 3 days	24 hours of close face-to-face
		q24h × 3 days		exposure to be effective..
				H.. influenzae requires 3 days
				of prophylaxis..
Influenza	Influenza	Oseltamivir	Rimantadine	Give to non-immunized
	A or B	(Tamiflu) 75 mg	100 mg (PO)	contacts and high-risk
		(PO) q24h for	q12h* for	contacts even if
		duration of	duration of	immunized.. Begin at onset
		outbreak (or	outbreak (or at	of outbreak or within
		at least 7 days	least 7–10 days	3 days of close contact
		after close	after close	to an infected person..
		contact to	contact to	Oseltamivir is active
		an infected	infected person)	against both influenza A
		person)..§	or	and B; rimantadine and
			Amantidine 200 mg	amantadine are only active
			(PO) q24h†	against influenza A..
			for 7–10 days or	Oseltamivir may be
			outbreak	ineffective due to
				resistance..

§   Dose for CrCl > 30–60 mL/min = 30 mg (PO) q24h; for CrCl >10–30 mL/min = 30 mg (PO) q48h..

	Chapter 6.  Prophylaxis and Immunizations					359
Table 6.3. Post-Exposure Prophylaxis (cont’d)
	Usual	Preferred		Alternate
Exposure	Organisms	Prophylaxis		Prophylaxis		Comments
Avian	Influenza A	Oseltamivir		Rimantadine		Oseltamivir may be
influenza	(H5N1)	(as for viral		or		ineffective due to
		influenza,		Amantadine† (as		resistance..
		above)		for viral influenza,
				above)
Swine	Influenza A	Oseltamavir		None		Amantadine/rimantadine
influenza	(H1N1)	above (as for				ineffective
		viral influenza,				Continue PEP for swine
		above)				influenza (H1N1) ×10 days
						post-close exposure..‡
Pertussis	B.. pertussis	Erythromycin		TMP–SMX 1		Administer as soon as
		500 mg (PO)		SS tablet (PO)		possible after exposure..
		q6h × 2 weeks		q12h × 2 weeks		Effectiveness is greatly
				or		reduced after 24 hours..
				Levofloxacin
				500 mg (PO)
				q24h × 2 weeks
Diphtheria	C.. diphtheriae	Erythromycin		Azithromycin 500		Administer as soon as
		500 mg (PO)		mg (PO) q24h ×		possible after exposure..
		q6h × 1 week		3 days		Effectiveness is greatly
		or				reduced after 24 hours..
		Benzathine
		penicillin 1..2 mu
		(IM) × 1 dose
TB	M..	Rifampin 600		Rifapentine		For INH, monitor SGOT/
	tuberculosis	mg (PO) q24h ×		900 mg (PO)		SGPT weekly × 4, then
		4 months§		q week		monthly.. Mild elevations
		or		plus		are common and resolve
		INH 300 mg		INH 900 mg (PO) q		spontaneously.. D/C INH
		(PO) q24h ×		week × 3 months		if SGOT/SGPT levels ≥ 5 ×
		9 months		(D..O..T..)		normal..

*For elderly, severe liver dysfunction, or CrCl < 10 cc/min, give 100 mg (PO) q24h..

†For age ≥ 65 years, give 100 mg (PO) q24h. . For renal dysfunction, give 200 mg (PO) load followed

by 100 mg q24h (CrCl 30–50 ml/min), 100 mg q48h (CrCl 15–29 ml/min), or 200 mg weekly (CrCl < 15 ml/min)..

‡Pediatric prophylaxis: < 15 kg: 30 mg PO qd for 10 days, > 15-24 kg: 45 mg PO qd for 10 days, 24-40 kg: 60 mg PO qd for 10 days, > 40 kg: same as adults..

§  INH preferred if patient uses contact lens, has HIV, or is taking medications that may interact with   rifampin.

360		A n t i b i o t i c	E s s e n t i a l s
Table 6.3. Post-Exposure Prophylaxis (cont’d)
	Usual	Preferred	Alternate
Exposure	Organisms	Prophylaxis	Prophylaxis	Comments
Gonorrhea	N..	Ceftriaxone	Spectinomycin 2	Administer as soon as
(GC)	gonorrhoeae	125 mg (IM) ×	gm (IM) × 1 dose	possible after sexual
		1 dose	or	exposure (≤ 72 hours)..
			Any oral	Ceftriaxone also treats
			quinolone ×	incubating syphilis..
			1 dose
Syphilis	T.. pallidum	Benzathine	Doxycycline	Administer as soon as
		penicillin	100 mg (PO)	possible after sexual
		2..4 mu (IM) × 1	q12h × 1 week	exposure.. Obtain HIV
		dose		serology..
Chancroid	H.. ducreyi	Ceftriaxone	Azithromycin 1	Administer as soon as
		250 mg (IM) ×	gm (PO) × 1 dose	possible after sexual
		1 dose	or	exposure.. Obtain HIV and
			Any oral	syphilis serologies..
			quinolone ×
			3 days
Non-	C.. trachomatis	Azithromycin	Any oral	Administer as soon as
gonococcal	U.. urealyticum	1 gm (PO) ×	quinolone ×	possible after sexual
urethritis	M.. genitalium	1 dose	1 week	exposure.. Also test for
(NGU)		or		gonorrhea/Ureaplasma..
		Doxycycline 100
		mg (PO) q12h ×
		1 week
Varicella	VZV	Preferred: For exposure < 72 hours,		Administer as soon as
(chicken-pox)		give varicella-zoster immune		possible after exposure
		globulin (VZIG) 625 mcg (IM) × 1		(≤ 72 hours).. Varicella
		dose to immuno-compromised		vaccine is a live
		hosts and pregnant women (esp..		attenuated vaccine and
		with respiratory conditions).. For		should not be given to
		others or exposure > 72 hours,		immunocompromised
		consider acyclovir 800 mg (PO) 5x/		or pregnant patients.. If
		day × 5–10 days		varicella develops, start
		Alternate: Varicella vaccine 0..5 mL		acyclovir treatment
				immediately..
		(SC) × 1 dose.. Repeat in 4 weeks

	Chapter 6.  Prophylaxis and Immunizations					361
Table 6.3. Post-Exposure Prophylaxis (cont’d)
	Usual	Preferred		Alternate
Exposure	Organisms	Prophylaxis		Prophylaxis		Comments
Hepatitis A	Hepatitis A	HAV vaccine		Immune serum		Give HAV vaccine alone
(HAV)	virus	1 mL (IM) × 1		globulin (IG) 0..02		if within 14 days after
		dose		mL/kg (IM) × 1		exposure..
				dose
Hepatitis B	Hepatitis B	Unvaccinated		Previously vaccinated
(HBV)	virus	Hepatitis B		Known responder (anti-HBsAg antibody levels
		immune		≥ 10 IU/mL): No treatment..
		globulin (HBIG)		Known non-responder (anti-HBsAg antibody
		0..06 mL/kg (IM)
				levels < 10 IU/mL): Treat as if unvaccinated..
		× 1 dose
		plus		Antibody status unknown: Obtain HBsAg antibody
		HBV vaccine (40		levels to determine immunity status.. If testing is
		mcg HBsAg/mL)		not possible or results are not available within 24
		deep deltoid (IM)		hours of exposure, give HBIG plus 1 dose of HBV
		at 0, 1, 6 months		vaccine (booster)..
		(can use
		10-mcg dose in
		healthy adults
		<40 years)
Hepatitis C	Hepatitis C	None
(HCV)	virus
Rocky	R.. rickettsia	Doxycycline 100		Any oral		Administer prophylaxis
Mountain		mg (PO) q12h ×		quinolone × 1		after removal of
spotted fever		1 week		week		Dermacentor tick..
Lyme disease	B.. burgdorferi	Doxycycline		Amoxicillin* 1 gm		If tick is in place ≥ 72 hours
		200 mg (PO) ×		(PO) q8h ×		or is grossly engorged,
		1 dose		3 days or		prophylaxis may be given
				Any oral 1st gen..		after tick is removed..
				cephalosporin* ×	Otherwise, prophylaxis is
				3 days		usually not recommended..
				or
				Azithromycin*
				500 mg (PO)
				q24h × 3 days

HDCV = human diploid cell vaccine, HRIG = human rabies immune globulin, PCEC = purified chick embryo cells, RVA = rabies vaccine absorbed.

*All or as much of the full dose of HRIG should be injected into the wound, and the remaining vaccine should be injected IM into the deltoid.. Do not give HRIG at the same site or through the same syringe with PCEC, RVA, or HDCV..

362		A n t i b i o t i c	E s s e n t i a l s
Table 6.3. Post-Exposure Prophylaxis (cont’d)
	Usual	Preferred	Alternate
Exposure	Organisms	Prophylaxis	Prophylaxis	Comments

*Although experience is limited, single-dose prophylaxis with these agents is probably also effective..

Zoonotic	B.. anthracis	Doxycycline 100	Any oral	Continued for the duration
diseases	Y.. pestis	mg (PO) q12h	quinolone for	of a naturally-acquired
(plague,		for duration of	duration of	exposure/outbreak.. See p..
anthrax)		exposure	exposure	363 for bioterrorist plague/
				anthrax recommendations..
Rabies	Rabies virus	No Previous	Previous	Following unprovoked
		Immunization	Immunization	or suspicious dog or cat
		HRIG 20 IU/kg*	PCEC 1 mL (IM) in	bite, immediately begin
		plus either	deltoid on days 0	prophylaxis if animal
		PCEC 1 mL (IM)	and 3	develops rabies during a
		in deltoid	or	10-day observation period..
		or	RVA 1 mL (IM) in	If dog or cat is suspected
		RVA 1 mL (IM) in	deltoid on days 0	of being rabid, begin
		deltoid	and 3	vaccination sequence
		or	or	immediately.. Raccoon,
		HDCV 1 mL (IM)	HDCV 1 mL (IM)	skunk, bat, fox, and most
		in deltoid	in deltoid on days	wild carnivore bites should
		PCEC, RVA,	0 and 3	be regarded as rabid, and
				bite victims should be
		HDCV given on
				vaccinated against rabies
		days 0, 3, 7, 14,
				immediately (contact
		and 28 post-
				local health department
		exposure
				regarding rabies potential
				of animals in your area).. All
				potential rabies wounds
				should immediately be
				thoroughly cleaned with
				soap and water.. Do not
				inject rabies vaccine IV
				(may cause hypotension/
				shock).. Serum sickness may
				occur with HDCV..

HDCV = human diploid cell vaccine, HRIG = human rabies immune globulin, PCEC = purified chick embryo cells, RVA = rabies vaccine absorbed.

*All or as much of the full dose of HRIG should be injected into the wound, and the remaining vaccine should be injected IM into the deltoid.. Do not give HRIG at the same site or through the same syringe with PCEC, RVA, or HDCV..

	Chapter 6.  Prophylaxis and Immunizations					363
Table 6.3. Post-Exposure Prophylaxis (cont’d)
	Usual	Preferred		Alternate
Exposure	Organisms	Prophylaxis		Prophylaxis		Comments
		BIOTERRORIST AGENTS
Anthrax	B.. anthracis	Doxycycline		Amoxicillin 1 gm		Duration of anthrax
Inhalation/		100 mg (PO)		(PO) q8h × 60		PEP based on longest
cutaneous		q12h × 60 days		days		incubation period of
		or Ciprofloxacin				inhaled spores in nares..
		500 mg (PO)
		q12h × 60 days
		or Levofloxacin
		500 mg (PO)
		q24h × 60 days
Tularemia	F.. tularensis	Doxycycline 100		Ciprofloxacin		Duration of PEP for
pneumonia		mg (PO) q12h ×		500 mg (PO)		tularemia is 2 weeks, not 1
		2 weeks		q12h × 2 weeks		week as for plague..
				or Levofloxacin
				500 mg (PO)
				q24h × 2 weeks
Pneumonic	Y.. pestis	Doxycycline		Chloramphenicol		Pneumonic plague should
plague		100 mg (PO)		500 mg (PO) q6h		be considered bioterrorism
		q12h × 7 days		× 7 days		since most natural cases of
		or Ciprofloxacin				plague are bubonic plague..
		500 mg (PO)
		q12h × 7 days
		or Levofloxacin
		500 mg (PO)
		q24h × 7 days
Smallpox	Variola virus	Smallpox		None		Smallpox vaccine is
		vaccine ≤4 days				protective when diluted
		after exposure				1:5..
Viral	Lassa fever	Ribavarin		None		Decrease maintenance
hemorrhagic		loading dose:				dose to 7..5 mg/kg (PO) q8h
fever		35mg/kg (PO)				if CrCl < 50/ml/min..
		(not to exceed
		2..5 g), then 15
		mg/kg (PO) (not
		to exceed 1g)
		q8h ×
		10 days