DESCRIPTION
Theridion is a homeopathic remedy made from the orange spider. It is indicated in the following conditions-

Oversensitivity to noise and touch seems to send shivers down the body, especially the teeth.

Head

A great remedy for cases of vertigo.
Vertigo as soon as eyes are closed . 
Nausea and vomiting on slightest movement.
Headache when lying down and if others are walking on floor, headache aggravates with slightest movements 
Seasickness and car sickness 

Mind

Panic disorder, time passes off too quickly of these individuals.
Insomnia, just not able to sleep although they are thoroughly exhausted.

Dose- As prescribed by physician. Can be taken along with allopathic medicines. 

Precautions: 

Maintain half an hour gap between food/drink/any other medicines and homeopathic medicine.
Avoid any strong smell in the mouth while taking medicine e.g. camphor, garlic, onion, coffee, hing.

Side effects- none reported 

Use under medical supervision.