- IC50 / IC90
The
concentration of a drug needed to inhibit viral replication by either 50%
(IC50) or 90% (IC90). IC stands for 'inhibitory concentration'.
- icterus
See ‘jaundice’.
- idiopathic
Disorder
whose cause is unknown.
- IDU
Injecting
drug user.
- IL28B
An inherited gene which all individuals have. There are three genotypes of IL28B; these influence response to hepatitis C and its treatment. People with CC genotype are more likely to spontaneously clear acute infection or (during chronic infection) respond well to interferon-based treatment. The other two genotypes are known as CT and TT.
- immediate release
Medication where the
active ingredient is released quite quickly, usually in less than
30 minutes.
- immune modulator
A
substance that changes an aspect of the way the immune system is working.
- immune reconstitution
Improvement
of the function of the immune system as a consequence of anti-HIV therapy.
- immune system
The
body's mechanisms for fighting infections and eradicating dysfunctional cells.
- immunoglobulin
Another
name for antibodies.
- immunologic response
The
effect of treatment on the immune system, particularly on the CD4 cell count.
- immunosuppressant
Drug that reduces or prevents
immune system activity.
- immunosuppression
A
reduction in the ability of the immune system to fight infections or tumours.
- in utero
Latin
term meaning in the womb.
- in vitro
Latin
term for experiments conducted in artificial environments, e.g. in test-tubes.
- in vivo
Latin
term for experiments conducted in humans or animals.
- incidence
The
proportion of people who acquire an infection or develop a condition during a
specified period of time. Incidence reflects newly acquired infections and conditions.
See also ‘prevalence’.
- inclusion criteria
The
conditions which a person must meet to join a clinical trial.
- indigestion
Pain or discomfort in the chest or stomach caused by eating or drinking.
- informed consent
A
patient’s agreement to continue with a clinical trial, a treatment or a
diagnostic test after having received a full written or verbal explanation of
the risks, benefits and the possible alternatives. See also ‘consent’.
- insomnia
Sleeplessness.
- insulin
A
hormone produced by the pancreas that tends to lower blood sugar levels.
- intent to treat analysis
All participants in a clinical trial are included in the final analysis, in the groups they were originally assigned to, whether or not they actually completed their course of treatment. Provides a better estimate of the real world effect of a treatment than an ‘on treatment analysis’.
- interaction
See
‘drug interaction’.
- interferon alfa
A natural protein
produced by the human body in response to infection. Manufactured interferon
alfa is a treatment against hepatitis B, hepatitis C, genital warts and some
cancers. See also ‘pegylated interferon’ – this is the form of the most
commonly used drug.
- interferon-free
A treatment regimen that does not include pegylated interferon.
- interleukin
A
type of cytokine. See also 'IL28B' for interleukin 28B.
- inter-quartile range
See ‘range’.
- intramuscular
Injected
into a muscle.
- intrapartum
During
the birth of a baby.
- intravenous
Injected
into a vein.
- intravitreal
Injected
into the eye.
- invasive
In
medical terms, going inside the body.
- investigator
Scientific researcher.
- isosporiasis
An
illness caused by the parasite Isospora belli.