Table 1: Giardia species and G. lamblia Genotypes

Species	G. lamblia genotype	Host
G. agilis		Amphibians
G. muris		Rodents
G. ardeae		Herons
G. microti		Rodents
G. psittaci		Psittacine birds
G. lamblia
	A	Humans, other mammals
	B	Humans, other mammals
	C	Dogs, cats
	D	Dogs, cats
	E	Livestock
	F	Cats
	G	Rats

Table 2. List of Comparative Studies of Treatment of Giardiasis, 1972-2008

Ref #	Date	Study type	Age of patients	% symptomatic	Location	# Subjects	Drug	Dose¹	Dur	Cure %²
14	1970	ROL	Both		Egypt	80	1. Quinacrine 2. Metronidazole 3. Furazolidone	100 mg tid 250 mg tid 100 mg qid	5 days 10 days 7 days	100 95 80
61	1972	ROL	Children	100	India	81	1. Metronidazole 2.Furazolidone	20 mg/kg tid 2 mg/kg tid	7 days 7 days	96 94
64, 65	1977	ROL	Children	100	India	100	1. Metronidazole 2. Tinidazole	50 mg/kg 50 mg/kg	single dose single dose	36 80
12	1978	ROL	Children	100	India	186	1. Tinidazole 2. Metronidazole	50 mg/kg 50 mg/kg	single dose single dose	88 47
94	1978	ROL	Children	100	India	60	1. Tinidazole 2. Metronidazole	50 mg/kg 50 mg/kg	single dose single dose	97 50
91	1979	AT	Children	100	Iran	160	1. Quinacrine 2. Metronidazole	8 mg/kg/d tid 250 mg tid	5 days 5 days	94 100
84	1979	AT	Adults	100	Finland	85	1. Metronidazole 2. Metronidazole 3. Tinidazole	2.4 gm 2.4 gm 2 gm	single dose 2 days Single dose	50 77 93
32	1981	ROL	Children	NS	US	58	1. Quinacrine 2. Furazolidone	6 mg/kg/d 8 mg/kg/d tid	10 days 10 days	77 89
95	1981	ROL	Adults	100	Finland	50	1. Metronidazole 2. Tinidazole	2 gm 2 gm	single dose single dose	76 88
85	1982	AT	Adults	100	Finland	105	1. Ornidazole 2. Tinidazole	1.5 gm 1.5 gm	single dose single dose	100 98
117	1983	ROL	Children	100	US	22	1. Furazolidone 2. Furazolidone	8 mg/kg/d tid 8 mg/kg/d tid	5 days 10 days	20 92
156	1985	ROL	Children	52	Bangladesh	33	1. Metronidazole 2. Tinidazole 3. Metronidazole 4. Tinidazole	2.4 gm 2 gm 2 gm/d 2 gm	single dose single dose 3 days single dose	65 94 93 100
13	1987	NS	Both	NS	Egypt	80	1. Metronidazole 2. Tinidazole 3. Ornidazole	500 mg/d 2 gm 1 gm	10 days Single dose Single dose	95 90 97
69	1989	ROL	Adults	100	India	20	1. Tinidazole 2. Tinidazole	2 gm 150 mg tid	single dose 7 days	100 100
63	1989	ROL	Adults	NS	Spain	23	1. Metronidazole 2. Mebendazole	250 mg tid 200 mg tid	7 days 1 day	89 14
140	1989	ROL	Children	100	Mexico	82	1. Furazolidone 2. Metronidazole	250 mg/d tid 750 mg tid	10 days 10 days	92 96
62	1990	ROL	Both	NS	Spain	19	1. Mebendazole 2. Metronidazole	200 mg tid 250 mg tid	5 days 7 days	12 91
129	1991	ROL	Children	87	Israel	75	1. Ornidazole 2. Metronidazole	40 mg/kg 20 mg/kg/d tid	single dose 7 days	92 100
126	1991	ROL	Both	61	India	75	1. Metronidazole 2. Tinidazole	50 mg/kg 50 mg/kg	single dose single dose	54 98
5	1992	ROL	Children	100	Iraq	44	1. Mebendazole 2. Metronidazole	200 mg tid 200 mg tid	5 days 5 days	91 86
70	1993	ROL	Children	NS	Bangladesh	334	1. Albendazole 2. Albendazole 3. Metronidazole 4. Albendazole 5. Albendazole 6. Metronidazole	600 mg 400 mg/d 375 mg/d 800 mg 400 mg/d 375 mg/d	single dose 3 days 5 days single dose 5 days 5 days	62 81 97 75 95 97
39	1994	ROL	Children	100	India	150	1. albendazole 2. Metronidazole	400 mg/d 7.5 mg/kg tid	5 days 5 days	97 97
87	1995	ROL	Children	100	Turkey	45	1. Mebendazole 2. Metronidazole 3. Furazolidone	200 mg tid 5 mg/kg tid 2 mg/kg qid	10 days 10 days 10 days	73 93 80
10	1995	ROL	Both	NS	Romania	83	1. Bacitracin zinc 2. Bacitracin 3. Neomycin. 4. Bacitracin Zn + Neo	240,000 U/d bid 240,000 U/d bid 240,000 U/d bid 120,000 U/d bid ea.	10 days 10 days 10 days 10 days	100 95 91 90
109	1995	ROL	Children	100	India	57	1. Albendazole 2. Metronidazole	400 mg/d 7.5 mg/kg tid	5 days 5 days	96 100
141	1996	ROL	Children	67	Iran	52	1. secnidazole 2. Metronidazole	30 mg/kg 20 mg/kg/d tid	single dose 10 days	100 94
21	1996	ROL	Children	100	Turkey	48	1. mebendazole 2. Mebendazole 3. Metronidazole 4. Ornidazole	100 mg tid 100 mg tid 15 mg/kg/d 40 mg/kg	1 day 10 days 7 days Single dose	42 58 93 100
30	1997	ROL	Children	61	Brazil	267	1. Secnidazole 2. Tinidazole	30 mg/kg 50 mg/kg	single dose single dose	92 90
137	1999	ROL	Children	66	Thailand	113	1. Albendazole 2. Tinidazole	400 mg/d 50 mg/kg	3 days Single dose	50 96
131	2001	ROL	Children	100	Cuba	110	1. nitazoxanide 2. Metronidazole	200 mg bid, ages 4-11, 100 mg bid, ages 2-3 250 mg bid ages 6-11, 125 mg,ages 2-5	3 days 5 days	71 75
146	2001	DBPC	Both	100	Egypt	36	Nitazoxanide	500 mg bid	3 days	71
147	2001	ROL	Children	NS	Iran	100	1. mebendazole 2. Metronidazole	200 mg tid 15 mg/kg/d tid	5 days 7 days	86 90
133	2002	NS	Children	100	Turkey	175	1. ornidazole 2. Ornidazole 3. Metronidazole	20, 25, or 30 mg/kg 25 mg/kg/d bid 20 mg/kg/d tid	single dose 5 days 7 days	96 100 89
136	2002	ROL	Children	48	Thailand	84	1. albendazole/praziquantel 2. albendazole 3. tinidazole	400 mg/20 mg/kg 800 mg 50 mg/kg	single dose single dose single dose	74 50 91
49	2003	ROL	Children	100	Cuba	146	1. mebendazole 2. secnidazole	200 mg tid 30 mg/kg	3 days Single dose	78 79
50	2003	ROL	Children	NS	Cuba	165	1. chloroquine 2. albendazole 3. tinidazole	10 mg/kg bid 400 mg/d 50 mg/kg	5 days 5 days Single dose	86 62 91
90	2004	ROL	Adults	100	Turkey	57	1. albendazole 2. metronidazole	400 mg/d 500 mg tid	5 days 5 days	96 100
174	2004	ROL	Children	34	Turkey	107	1. albendazole 2. metronidazole	10 mg/kg/d 20 mg/kg/d tid	5 days 5 days	90 89
17	2006	DBPC	Adults	53	Turkey	65	1. metronidazole + Saccharomyces 2. metronidazole	Mtz 750 mg tid +Sac 250 mg bid 750 mg tid	10 days 10 days	100 83
28	2006	ROL	Children	?	Cuba	122	1. mebendazole 2. tinidazole	200 mg tid 50 mg/kg	1 day Single dose	64 82
27	2006	ROL	Children	100	Cuba	122	1. mebendazole 2. quinacrine	200 mg tid 2 mg/kg tid	5 days 5 days	79 84
7	2006	ROL	Both	100	Iran	120	1. albendazole 2. metronidazole	400 mg/d 250 mg tid	5 days 5 days	90 77
48	2008	ROL	Children	100	Cuba	137	1. tinidazole 2. nitazoxanide	50 mg/kg 7.5 mg/kg bid	single dose 3 days	90 78

Abbreviations: ROL (Randomized open label), AT (alternating treatment), DBPC (double blind placebo controlled), NS (not stated)

¹ For studies including adults and children, the adult dose is given.

² For most studies, the cure rate was determined by parasitologic cure shortly after completion of treatment.

Table 3: Drugs Used for Treatment of Giardiasis

Class	Drug	Oral bioavailability (%)	Half life	Dose (adult and max ped dose) and duration	Availability in US	FDA approved for giardiasis	Common side effects	Concerns
Nitroimidazole	Metronidazole	100	6-10 h	5 mg/kg tid (250 mg) 5 to 10 days	Y	N	metallic taste, nausea, anorexia	DNA mutagnesis and possibility of carcinogenesis
	Tiniazole	100	12 h	50 mg/kg (2 gm) single dose	Y	Y	metallic taste, nausea, anorexia	DNA mutagnesis and possibility of carcinogenesis
	Ornidazole	100	11-14 h	40 mg/kg (2 gm) single dose	N	N	metallic taste, nausea, anorexia	DNA mutagnesis and possibility of carcinogenesis
	Secnidazole	100	14-20 h	30 mg/kg (1.5 gm) single dose	N	N	metallic taste, nausea, anorexia	DNA mutagnesis and possibility of carcinogenesis

Benzimidazole	Albendazole	1-5	8-12 h	15 mg/kg qd (400 mg) 5 days	Y	N		Embryotoxicity

Aminoglycoside	Paromomycin	0	NA	10 mg/kg tid (500 mg) 5 to 10 days	Y	N

Nitrofuran	Furazolidone		10 m	2 mg/kg qid (100 mg) 7 to 10 days	N¹	Y		Adverse effect on reproduction, mutagenesis

Others	Nitazoxanide	parent drug not dectected	1.3-1.8 h	Adult 500 mg bid, 100 mg bid (ages 1-3), 200 mg bid (ages 4-11) 3 days	Y	Y
	Quinacrine	good	5-14 d	2 mg/kg tid (100 mg) 5 to 7 days	N¹	Y	nausea and vomiting	Toxic psychosis, common nausea and vomiting

Abbreviations: Y (yes), N (no), NA (not applicable), h (hours), m (minutes), d (days)

¹ No longer generally available in the US, but available from Panorama Compounding Pharmacy in Lake Balboa, CA; Phone (800) 247-9767 (availability confirmed on September 18, 2009).

rev. 10/09