An anxiogenic substance is one that causes anxiety

Anxiety

Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...

. Anxiogenic effects can be measured by, for example, the hole-board test in rats and mice. A number of agents are used to provoke anxiety (anxiogens) or panic (panicogens) in experimental models . Some of the most common substances are: sodium lactate

Sodium lactate

Sodium lactate is the sodium salt of lactic acid produced by fermentation of a sugar source, such as corn or beets, and then neutralizing the resulting lactic acid to create a compound having the formula NaC3H5O3. As a food additive, sodium lactate has the E number E325 and naturally is a liquid...

, carbon dioxide

Carbon dioxide

Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 (as carbogen

Carbogen

Carbogen, also called Meduna's Mixture after its inventor Ladislas Meduna, is a mixture of carbon dioxide and oxygen gas. Meduna's original formula was 30% CO2 and 70% oxygen, but the term carbogen can refer to any mixture of these two gases, from 1.5% to 50% CO2.- Mechanism :When carbogen is...

), L-DOPA, caffeine

Caffeine

Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...

, Modafinil

Modafinil

Modafinil is an analeptic drug manufactured by Cephalon, and is approved by the U.S. Food and Drug Administration for the treatment of narcolepsy, shift work sleep disorder, and excessive daytime sleepiness associated with obstructive sleep apnea...

, GABA antagonists such as DMCM

DMCM

DMCM is a drug from the beta-carboline family. It acts as an inverse agonist of benzodiazepine receptors, meaning that it causes the opposite effects to the benzodiazepine class of drugs...

, FG-7142 and ZK-93426

ZK-93426

ZK-93426 is a drug from the beta-carboline family. It acts as a weak partial inverse agonist of benzodiazepine receptors, meaning that it causes the opposite effects to the benzodiazepine class of drugs and has anxiogenic properties, although unlike most benzodiazepine antagonists it is not a...

, serotonergic

Serotonergic

Serotonergic or serotoninergic means "related to the neurotransmitter serotonin". A synapse is serotonergic if it uses serotonin as its neurotransmitter...

 agents such as mCPP

1-(3-Chlorophenyl)piperazine

meta-Chlorophenylpiperazine is a psychoactive drug of the phenylpiperazine class. It was initially developed in the late-1970s and used in scientific research before being sold as a designer drug in the mid-2000s...

 and LY-293,284

LY-293,284

LY-293,284 is a research chemical developed by the pharmaceutical company Eli Lilly and used for scientific studies. It acts as a potent and selective 5-HT1A receptor full agonist...

, adrenergic agents such as yohimbine

Yohimbine

Yohimbine is an alkaloid with stimulant and aphrodisiac effects found naturally in Pausinystalia yohimbe . It is also found naturally in Rauwolfia serpentina , Alchornea floribunda , along with several other active alkaloids...

, antipsychotics/dopamine antagonist

Dopamine antagonist

A dopamine antagonist is a drug which blocks dopamine receptors by receptor antagonism. There are five known types of dopamine receptors in the human body; they are found in the brain, peripheral nervous system, blood vessels, gastrointestinal tract and the kidney.-Uses and examples:* Used as...

 such as ecopipam

Ecopipam

Ecopipam is a synthetic benzazepine derivative drug that acts as a selective dopamine D1/D5 receptor antagonist, with little affinity for either dopamine D2-like or 5-HT2 receptors...

 and reserpine

Reserpine

Reserpine is an indole alkaloid antipsychotic and antihypertensive drug that has been used for the control of high blood pressure and for the relief of psychotic symptoms, although because of the development of better drugs for these purposes and because of its numerous side-effects, it is rarely...

, and cholecystokinin

Cholecystokinin

Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...

 (CCK) (especially the tetrapeptide and octapeptide fragments CCK-4

CCK-4

Cholecystokinin tetrapeptide is a peptide fragment derived from the larger peptide hormone cholecystokinin...

 and CCK-8). Studies have shown that 10 mL/kg of 0.5 molar

Mole (unit)

The mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as an amount of a substance that contains as many elementary entities as there are atoms in 12 grams of pure carbon-12 , the isotope of carbon with atomic weight 12. This corresponds to a value...

 sodium lactate infused intravenously over a 20-minute period will provoke a panic attack

Panic attack

Panic attacks are periods of intense fear or apprehension that are of sudden onset and of relatively brief duration. Panic attacks usually begin abruptly, reach a peak within 10 minutes, and subside over the next several hours...

 in most patients with panic disorder but not healthy control

Scientific control

Scientific control allows for comparisons of concepts. It is a part of the scientific method. Scientific control is often used in discussion of natural experiments. For instance, during drug testing, scientists will try to control two groups to keep them as identical and normal as possible, then...

 subjects.

Antibiotics drugs such as Fluoroquinolones can cause from short-term to long-term anxiety and panic disorders as a side effect. This its due to a posible antagonism of GABA receptor

GABA receptor

The GABA receptors are a class of receptors that respond to the neurotransmitter gamma-aminobutyric acid , the chief inhibitory neurotransmitter in the vertebrate central nervous system...

 and toxicity of the central nervous system

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

. This effect its potentiated with the combined use of Non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drug

Nonsteroidal anti-inflammatory drugs, usually abbreviated to NSAIDs or NAIDs, but also referred to as nonsteroidal anti-inflammatory agents/analgesics or nonsteroidal Anti-inflammatory medicines , are drugs with analgesic and antipyretic effects and which have, in higher doses, anti-inflammatory...

.

The GABA antagonist

GABA antagonist

GABA antagonists are drugs which inhibit the action of GABA. In general these drugs produce stimulant and convulsant effects, and are mainly used for counteracting overdose of sedative drugs....

, Flumazenil

Flumazenil

Flumazenil is a benzodiazepine antagonist available for injection only, and the only benzodiazepine receptor antagonist on the market today.It was first introduced in 1987 by Hoffmann-La Roche under the trade name Anexate, but only approved by...

 cause panic attacks in patients with panic disorder.

Anxiolytic

Anxiolytic

An anxiolytic is a drug used for the treatment of anxiety, and its related psychological and physical symptoms...

 substances have the opposite effect: they reduce anxiety. The most common class of anxiolytic drugs are benzodiazepines and barbiturates.